Patent Publication Number: US-2020278369-A1

Title: Conveyor assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/434,968, filed Feb. 16, 2017, now pending, which claims the benefit of U.S. Provisional Application Nos. 62/332,831, filed May 6, 2016, and 62/297,348, filed Feb. 19, 2016, the contents of each of which applications is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     Embodiments of this disclosure relate to laboratory automated instruments, systems, and methods for processing a sample. 
     BACKGROUND 
     Laboratory automated instruments and systems can have automated conveyor assemblies that transport samples among various positions within a laboratory. For example, the samples can be contained in receptacles, and the receptacles can be coupled to carriers (e.g., pucks). To transport the carriers and, in turn, the receptacles containing the samples, the carriers are placed on the conveyor assembly, and the conveyor assembly transports the carriers and the receptacles coupled to the carriers among the various positions within the laboratory. 
     SUMMARY 
     In some embodiments, an automated sample processing system includes a first instrument that includes a first automated pipettor configured to aspirate at least a portion of a sample from a first sample containing receptacle and dispense the portion of the first sample into a first processing receptacle. The automated sample processing system also includes a second instrument includes a second automated pipettor configured to aspirate at least portions of samples from processing receptacles containing samples at a first processing position within the second instrument and dispense at least portions of samples into assay receptacles. The second instrument is further configured to perform first assays on the portions of the samples contained within assay receptacles. The automated sample processing system also includes a first conveyor assembly configured to transport a first carrier coupled to the first processing receptacle containing the portion of the first sample dispensed by the first automated pipettor from the first instrument to a position outside the first instrument. The automated sample processing system also includes a second conveyor assembly configured to receive the first carrier coupled to the first processing receptacle from the first conveyor assembly at the position outside the first instrument, and to transport the first carrier to a first position outside the second instrument. 
     The automated sample processing system also includes a third conveyor assembly. The third conveyor assembly is configured to receive the first carrier from the second conveyor assembly at the first position outside the second instrument. The third conveyor assembly is also configured to transport the first carrier to the first processing position within the second instrument at which the second automated pipettor of the second instrument aspirates at least a portion of the first sample from the first processing receptacle for subsequently dispensing the portion of the first sample into an assay receptacle. The third conveyor assembly is also configured to, after the second automated pipettor of the second instrument aspirates at least a portion of the first sample from the first processing receptacle, transport the first carrier coupled to the first processing receptacle from the first processing position to a second position outside the second instrument. The third conveyor assembly is also configured to transfer the first carrier at the second position outside the second instrument to the second conveyor assembly. 
     The second instrument can be configured to perform first assays by subjecting samples contained within assay receptacles to nucleic acid amplification reaction conditions. The first instrument can be further configured to couple the first processing receptacle with the first carrier. The first instrument can further include an input bay configured to manually receive the first sample containing receptacle. The first instrument can further include an input bay configured to automatically receive the first sample containing receptacle. 
     The automated sample processing system can further include a third instrument that includes a third automated pipettor configured to aspirate at least portions of samples from processing receptacles containing samples at a second processing position within the third instrument and dispense the portions of samples into second assay receptacles. The third instrument is further configured to perform second assays on samples contained within assay receptacles. 
     The first assays can be different than the second assays. The third instrument can be configured to perform the second assays by subjecting samples contained within assay receptacles to nucleic acid amplification reaction conditions. Subjecting samples contained within assay receptacles to nucleic acid amplification reaction conditions of the first assay can include adding a first reagent to samples contained within assay receptacles, and subjecting samples contained within assay receptacles to nucleic acid amplification reaction conditions of the second assay can include adding a second reagent, different than the first reagent, to samples contained within assay receptacles. The first assays can be configured to determine the presence of a first analyte, and the second assays can be configured to determine the presence of a second analyte different than the first analyte. 
     The first assays can be the same as the second assays. 
     The automated sample processing system can further include a fourth conveyor assembly configured to receive a second carrier coupled to a second processing receptacle from the second conveyor assembly at a first position outside the third instrument. The fourth conveyor assembly is further configured to transport the second carrier to the second processing position within the third instrument at which the third automated pipettor of the third instrument aspirates at least a portion of a second sample from the second processing receptacle for subsequently dispensing the portion of the second sample into a second assay receptacle. And the fourth conveyor assembly is further configured to, after the third automated pipettor of the third instrument aspirates the portion of the second sample from the second processing receptacle, transport the second carrier from the second processing position to a second position outside the third instrument. The first automated pipettor of the first instrument is further configured to aspirate at least a portion of the second sample from the second sample containing receptacle and dispense the portion of the second sample into the second processing receptacle. The first conveyor assembly is further configured to transport the second carrier coupled to the second processing receptacle containing the portion of the second sample dispensed by the first automated pipettor from the first instrument to the position outside the first instrument. The second conveyor assembly is further configured to receive the second carrier coupled to the second processing receptacle from the first conveyor assembly at the position outside the first instrument, and transport the second carrier to the first position outside the third instrument. 
     The first instrument cam include a writer configured to transfer a first identifier to at least one of the first carrier and the first processing receptacle, and to transfer a second identifier to at least one of the second carrier and the second processing receptacle. The writer can be a printer configured to print the first identifier on at least one of the first carrier and the first processing receptacle, and to print the second identifier on at least one of the second carrier and the second processing receptacle. The writer can be configured to transfer the first identifier to the first carrier and the second identifier to the second carrier. The first carrier can include a first RFID tag, and the second carrier can include a second RFID tag. The writer can include an RFID writer configured to transmit the first identifier to the first RFID tag and the second identifier to the second RFID tag. 
     The second conveyor system can include a first portion configured to transport carriers from the position outside the first instrument to the first position outside the second instrument. The second conveyor system can also include a second portion configured to transport carriers from the first position outside the second instrument to the second position outside the second instrument. And the second conveyor system can include a diverter configured to transfer the first carrier from the first portion of the second conveyor assembly to the third conveyor assembly based on the first identifier. The divert is also configured to transfer the second carrier from the first portion of the second conveyor assembly to the second portion of the second conveyor assembly based on the second identifier. 
     The automated sample processing system can further include a control system configured to transmit a control signal to the diverter. The diverter can be configured to transfer the first carrier from the first portion of the second conveyor assembly to the third conveyor assembly based on the control signal. The diverter can be also configured to transfer the second carrier from the first portion of the second conveyor assembly to the second portion of the second conveyor assembly based on the control signal. The second conveyor assembly can further include a sensor configured to detect the first identifier of the first carrier and the second identifier of the second carrier, and to transmit a sensor signal to the control system based on the detected first identifier and the detected second identifier. The control system is configured to adjust the control signal transmitted to the diverter based on the sensor signal received from the sensor. The sensor of the second conveyor assembly can include an RFID antenna. The sensor of the second conveyor assembly can also be an image sensor. 
     The third conveyor assembly can include a sensor configured to detect the first identifier of the first carrier positioned at the first processing position. The second instrument can be configured to start aspirating the portion of the first sample from the first processing receptacle containing the portion of the first sample at the first processing position within the second instrument based on the detected first identifier. The sensor of the third conveyor assembly can include an RFID antenna. The sensor of the third conveyor assembly can also be an image sensor. 
     The second conveyor system can further include a first portion configured to transport carriers from the second position outside the second instrument to the first position outside the third instrument, and a second portion configured to transport carriers from the first position outside the third instrument to the second position outside the third instrument. The second conveyor system can further include a diverter configured to transfer the second carrier from the first portion of the second conveyor assembly to the fourth conveyor assembly based on the second identifier of the second carrier. The divert can also be configured to transfer the first carrier from the first portion of the second conveyor assembly to the second portion of the second conveyor assembly based on the first identifier. 
     The automated sample processing system can also include a control system configured to transmit a control signal to the diverter. The diverter can be configured to transfer the second carrier from the first portion of the second conveyor assembly to the fourth conveyor assembly based on the control signal, and configured to transfer the first carrier from the first portion of the second conveyor assembly to the second portion of the second conveyor assembly based on the control signal. The second conveyor assembly further includes a sensor configured to detect the first identifier of the first carrier and the second identifier of the second carrier, and to transmit a second sensor signal to the control system based on the detected first identifier and the detected second identifier. The control system can be configured to adjust the control signal transmitted to the diverter based on the second sensor signal received from the sensor of the second conveyor assembly. The sensor of the second conveyor assembly includes an RFID antenna. The sensor of the second conveyor assembly can also be an image sensor. 
     The fourth conveyor assembly can include a sensor configured to detect the second identifier of the second carrier positioned at the second processing position. And the third instrument can be configured to start aspirating the portion of the second sample from the second processing receptacle containing the second sample at the second processing position within the third instrument based on the detected second identifier. The sensor of the fourth conveyor assembly can include an RFID antenna. The sensor of the fourth conveyor assembly can also be an image sensor. 
     The third instrument can further include a housing defining a substantially enclosed volume, and the third automated pipettor can be positioned in the volume. 
     The third conveyor assembly can include a first conveyor subassembly that includes an input portion configured to transport the first carrier from the second conveyor assembly to a first transfer position. The first conveyor subassembly can also include an output portion configured to transport the first carrier from a second transfer position to the second position outside the second instrument. The third conveyor assembly can also include a second conveyor subassembly configured to transport the first carrier between a third transfer position and the first processing position within the instrument. The third conveyor assembly can also include a diverter configured to transport the first carrier from the first transfer position to the third transfer position while simultaneously transporting another carrier from the third transfer position to the second transfer position. The second conveyor subassembly can include a gripper configured to secure the first carrier to the first processing receptacle as a distal end of the second automated pipettor is withdrawn from the first processing receptacle. The second conveyor subassembly can also include a movable track configured to transport the first carrier between the third transfer position and the first processing position within the instrument. 
     The first carrier can be a puck. 
     The first instrument can further include a first housing, and the first automated pipettor is positioned in the first housing. The second instrument can further include a second housing, and the second automated pipettor is positioned in the second housing. 
     The first instrument can further include a sample processing station configured to decap and cap at least one of the first sample containing receptacle and the first processing receptacle. 
     In some embodiments, an automated sample processing system includes a first conveyor assembly configured to transport a first carrier coupled to a first processing receptacle containing a first sample, and a second carrier coupled to a second processing receptacle containing a second sample. The automated sample processing system includes a second conveyor assembly configured to receive the first carrier from the first conveyor assembly, transport the first carrier to a first processing position, and return the first carrier to the first conveyor assembly. The automated sample processing system also includes a first instrument that includes a first automated pipettor configured to aspirate at least a portion of the first sample from the first processing receptacle at the first processing position and dispense the portion of the first sample into a first assay receptacle. The first processing position is within the first instrument. And the first instrument is further configured to perform a first assay on the first sample contained within the first assay receptacle to determine the presence of a first analyte in the first sample. The automated sample processing system includes a third conveyor assembly configured to receive the second carrier from the first conveyor assembly, transport the second carrier to a second processing position, and return the second carrier to the first conveyor assembly. The automated sample processing system includes a second instrument that includes a second automated pipettor configured to aspirate at least a portion of the second sample from the second processing receptacle at the second processing position and dispense the portion of the second sample into a second assay receptacle. The second processing position is within the second instrument. And the second instrument is further configured to perform a second assay on the second sample contained within the second assay receptacle to determine the presence of a second analyte in the second sample. 
     The first assay can include subjecting the first sample contained within the first assay receptacle to nucleic acid amplification reaction conditions. The first assay can be different than the second assay. 
     The second assay can include subjecting the second sample contained within the second assay receptacle to nucleic acid amplification reaction conditions. 
     The first analyte and the second analyte can be the same analytes, or the first analyte and the second analyte can be different analytes. 
     At least one of the first processing receptacle and the first carrier can include a first identifier, and at least one of the second processing receptacle and the second carrier can include a second identifier. The first conveyor system can also include a first portion configured to transport the first carrier and the second carrier to a first position upstream from the second conveyor system. The first conveyor system can also include a second portion configured to transport the first carrier and the second carrier to a second position upstream from the third conveyor system. And the first conveyor system can include a first diverter configured to transfer the first carrier from the first portion of the first conveyor assembly to the second conveyor assembly based on the first identifier. The diverter is also configured to transfer the second carrier from the first portion of the first conveyor assembly to the second portion of the first conveyor assembly based on the second identifier. The automated sample processing system can also include a control system configured to transmit a first control signal to the first diverter. The first diverter is configured to transfer the first carrier from the first portion of the first conveyor assembly to the second conveyor assembly based on the first control signal, and the first diverter configured to transfer the second carrier from the first portion of the first conveyor assembly to the second portion of the first conveyor assembly based on the first control signal. The first conveyor assembly further includes a first sensor configured to detect the first identifier when the first carrier is at the first position upstream from the second conveyor system, detect the second identifier when the second carrier is at the first position upstream from the second conveyor system, and transmit a first sensor signal to the control system based on the detected first identifier and the detected second identifier. The control system is also configured to adjust the first control signal transmitted to the first diverter based on the first sensor signal received from the first sensor. 
     The first conveyor system can further include a third portion configured to transport the first carrier and the second carrier to a third position downstream from the second instrument. The first conveyor system can further include a second diverter configured to transfer the first carrier from the second portion of the first conveyor assembly to the third portion of the first conveyor assembly based on the first identifier. The second diverter is also configured to transfer the second carrier from the second portion of the first conveyor assembly to the third conveyor assembly based on the second identifier. 
     The control system can be further configured to transmit a second control signal to the second diverter. The second diverter is configured to transfer the second carrier from the second portion of the first conveyor assembly to the third conveyor assembly based on the second control signal, and configured to transfer the first carrier from the second portion of the first conveyor assembly to the third portion of the first conveyor assembly based on the second control signal. The first conveyor assembly can further include a second sensor configured to detect the first identifier when the first carrier is at second position upstream from the third conveyor system, detect the second identifier when the second carrier is at the second position upstream from the third conveyor system, and transmit a second sensor signal to the control system based on the detected first identifier and the detected second identifier. The control system can also be configured to adjust the second control signal transmitted to the second diverter based on the second sensor signal received from the second sensor. 
     The second conveyor assembly can further include a third sensor configured to detect the first identifier of the first carrier positioned at the first processing position. The first instrument is configured to start aspirating the portion of the first sample from the first processing receptacle at the first processing position based on the detected first identifier. 
     The third conveyor assembly can further include a fourth sensor configured to detect the second identifier of the second carrier positioned at the second processing position, and wherein the second instrument is configured to start aspirating the portion of the second sample from the second processing receptacle at the second processing position based on the detected second identifier. 
     In some embodiments, a conveyor assembly transports a plurality of carriers coupled to respective processing receptacles from a host conveyor assembly outside an instrument to a processing position within the instrument. The conveyor assembly includes a buffer conveyor subassembly configured to transport the plurality of carriers coupled to the respective receptacles from the host conveyor assembly to a first transfer position and configured to transport the plurality of carriers coupled to the respective receptacles from a second transfer position to the host conveyor assembly. The conveyor assembly also includes a spur conveyor subassembly configured to transport the plurality of carriers coupled to the respective receptacles from a third transfer position to the processing position within the instrument. The spur conveyor subassembly includes a diverter configured to transport one of the plurality of carriers coupled to one of the respective receptacles from the first transfer position to the third transfer position while simultaneously transporting another one of the plurality of carriers coupled to another one of the respective receptacles from the third transfer position to the second transfer position. 
     The buffer conveyor subassembly can be mounted to an outer surface of the instrument. The third transfer position can be outside of the instrument. The spur conveyor subassembly can further include a cover that encloses a portion of a path within the instrument between the third transfer position and the processing position. The cover can define an opening configured to allow a distal end of a pipettor of the instrument to pass. The distal end of the pipettor can include a disposable tip. The cover can have a substantially inverted U-shape. 
     The spur conveyor subassembly can further include a sensor configured to detect an identifier of one of the plurality of carriers positioned at the processing position of the instrument. The sensor can include an RFID reader. 
     The buffer conveyor subassembly can include a single movable track. A portion of the diverter can overlap the single movable track forming an input portion and an output portion of the buffer conveyor subassembly. The input portion of the buffer conveyor subassembly can have a length sufficient to queue a plurality of carriers. The instrument can be configured to aspirate at least portions of samples from processing receptacles coupled to carriers at the processing position and to dispense the portions of the samples into cavities defined by an assay receptacle. The length of the input portion of the buffer conveyor subassembly can be sufficient to queue a number of carriers at least equal to a number of cavities defined by the assay receptacle. 
     The diverter can define a first concave recess and a second concave recess. The first concave recess is configured to receive a carrier at the first transfer position, and the second concave recess is configured to receive a carrier at the third transfer position. The diverter can further define a third concave recess. The first, second, and third concave recess of the diverter can be equally spaced about a periphery of the diverter. 
     The diverter can be configured to rotate about an axis. The diverter can be configured to rotate about the axis in only one direction, or the diverter can be configured to rotate about the axis in two directions. The conveyor assembly can further include a base and a drive assembly coupled to the base and configured to rotate the diverter. The diverter can be rotatably coupled to the base. 
     The spur conveyor can define a single path along which the plurality of carriers coupled to the respective receptacles are transported. The spur conveyor further can include a portion defining a recess configured to receive a portion a receptacle coupled a carrier positioned at the processing position within the instrument. 
     In some embodiments, the spur conveyor subassembly can further include a movable gripper configured to grasp one of the plurality carriers at the third transfer position and transport the one of the plurality carriers to the processing position within the instrument. The gripper can include at least two movable prongs configured to apply pressure to the carrier grasped by the gripper. Each of the at least two movable prongs can include a portion having a protrusion configured to mate with a groove defined by the carrier grasped by the gripper such that as a distal end of a pipettor of the instrument is removed from a respective processing receptacle of the carrier grasped by the gripper. The gripper can hold the carrier to the spur conveyor subassembly. The at least two movable prongs can be further configured to contact a receptacle coupled to the carrier grasped by the gripper. 
     In other embodiments, the spur conveyor subassembly includes a movable track configured to transport one of the plurality carriers between the third transfer position the processing position within the instrument. 
     In some embodiments, a sample processing method includes verifying that an identifier of a first carrier detected at a first position on a host conveyor assembly is associated with a first sample on which a first assay is scheduled to be performed with a first instrument. The method also includes diverting the first carrier from the host conveyor assembly to a first intermediate conveyor assembly, and transporting the first carrier to a first processing position within the first instrument using the first intermediate conveyor assembly. The method also includes verifying that an identifier of the first carrier detected at the first processing position is associated with the first sample on which the first assay is scheduled to be performed with the first instrument. The method also includes, at the first processing position, transferring at least a portion of the first sample from a first processing receptacle coupled to the first carrier to a first assay receptacle using a first automated pipettor of the first instrument. The method also includes performing the first assay by subjecting the portion of the first sample in the first assay receptacle to nucleic acid amplification reaction conditions using the first instrument. And the method includes transporting the first carrier from the first processing position to the host conveyor assembly using the first intermediate conveyor assembly. 
     The method can also include verifying that an identifier of a second carrier detected at the first position on the host conveyor assembly is associated with a second sample on which the first assay is scheduled to be performed with the first instrument. The method can also include diverting the second carrier from the host conveyor assembly to the first intermediate conveyor assembly. The method can also include transporting the second carrier to the first processing position within the first instrument using the intermediate conveyor assembly, and verifying that an identifier of the second carrier detected at the first processing position is associated with the second sample on which the first assay is scheduled to be performed with the first instrument. The method can also include, at the first processing position, transferring at least a portion of the second sample from a second processing receptacle coupled to the second carrier to the first assay receptacle using the first automated pipettor. The method can also include performing the first assay by subjecting the portion of the second sample in the first assay receptacle to nucleic acid amplification reaction conditions using the first instrument, and transporting the second carrier from the first processing position to the host conveyor assembly using the intermediate conveyor assembly. 
     Transporting the second carrier to the first processing position within the first instrument using the intermediate conveyor assembly can occur after the transporting the first carrier from the first processing position to the host conveyor assembly using the first intermediate conveyor assembly. Transporting the second carrier to the first processing position within the first instrument using the intermediate conveyor assembly can also occur concurrently with the transporting the first carrier from the first processing position to the host conveyor assembly using the first intermediate conveyor assembly. 
     The method can also include determining whether an identifier of a second carrier detected at the first position on the host conveyor assembly is associated with a second sample on which the first assay is scheduled to be performed with a first instrument. The method can also include bypassing the second carrier past the intermediate conveyor assembly to a second position on the host conveyor assembly when the identifier of the second carrier detected at the first position on the host conveyor assembly is not associated with the second sample on which the first assay will be performed. The method can also include determining whether an identifier of the second carrier detected at the second position on the host conveyor assembly is associated with a third sample on which a second assay is scheduled to be performed with a second instrument. The method can also include diverting the second carrier from the host conveyor assembly to a second intermediate conveyor assembly. The method can also include transporting the second carrier to a second processing position within the second instrument using the second intermediate conveyor assembly, and determining whether an identifier of the second carrier detected at the second processing position is associated with the third sample on which the second assay is scheduled to be performed with the first instrument. The method can also include, at the second processing position, transferring at least a portion of the third sample from a second processing receptacle coupled to the second carrier to a second assay receptacle using a second automated pipettor of the second instrument. The method can also include performing the second assay by subjecting the portion of the third sample in the second assay receptacle to nucleic acid amplification reaction conditions using the second instrument. The method can also include transporting the second carrier coupled to the second processing receptacle from the second processing position to the host conveyor assembly using the intermediate conveyor assembly. 
     The second assay can be different than the first assay. Performing the first assay can include subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a polymerase chain reaction, and performing the second assay can include subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a transcription-based amplification reaction. 
     The second assay can be the same as the first assay. Performing the first assay can include subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a polymerase chain reaction, and performing the second assay includes subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a polymerase chain reaction. 
     The first assay can include subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a transcription-based amplification reaction, and performing the second assay can includes subjecting a respective portion of a sample in an assay receptacle to nucleic acid amplification reaction conditions that promotes a transcription-based amplification reaction. 
     The method can also include, before the transporting the second carrier to the first processing position within the first instrument using the intermediate conveyor assembly, queuing a predetermined number of carriers on the intermediate conveyor assembly. The predetermined number can correspond to a number of sample receiving cavities defined by the first assay receptacle. 
     In some embodiments, an automated sample processing method includes aspirating at least a portion of a first sample from a first sample containing receptacle using a first automated pipettor of a first instrument, and dispensing the portion of the first sample into a first processing receptacle using the automated pipettor of the first instrument. The method can also include transporting a first carrier coupled to the first processing receptacle containing the first sample from a position inside the first instrument to a host conveyor assembly using a first intermediate conveyor assembly, and transporting the first carrier from the host conveyor assembly to a first processing position within a second instrument using a second intermediate conveyor assembly. The method can also include aspirating at least a portion of the first sample from the first processing containing receptacle at the first processing position using a second automated pipettor of the second instrument, and dispensing the portion of the first sample into a first assay receptacle using the second automated pipettor of the second instrument. The method can also include performing a first assay on the portion of the first sample in the first assay receptacle using the second instrument, and transporting the first carrier from the first processing position to the host conveyor assembly using the second intermediate conveyor assembly. 
     Performing the first assay can include subjecting the portion of the first sample in the first assay receptacle to nucleic acid amplification reaction conditions. 
     The method can also include coupling the first processing receptacle with the first carrier using the first instrument. The method can also include manually inserting the first sample containing receptacle into an input bay of the first instrument, or automatically inserting the first sample containing receptacle into an input bay of the first instrument. 
     The method can also include aspirating at least a portion of a second sample from a second sample containing receptacle using the first automated pipettor of the first instrument, and dispensing the portion of the second sample into a second processing receptacle using the first automated pipettor of the first instrument. The method can also include transporting a second carrier coupled to the second processing receptacle containing the second sample from the position inside the first instrument to the host conveyor assembly using the first intermediate conveyor assembly, and transporting the second carrier from the host conveyor assembly to a second processing position within a third instrument using a third intermediate conveyor assembly. The method can also include aspirating at least a portion of the second sample from the second processing receptacle at the second processing position using a third automated pipettor of the third instrument, and dispensing the portion of the second sample into a second assay receptacle using the third automated pipettor of the instrument. The method can also include performing a second assay on the portion of the second sample in the second assay receptacle using the third instrument, and transporting the second carrier from the second processing position to the host conveyor assembly using the third intermediate conveyor assembly. 
     The first assay can be different than the second assay. The first assay can be configured to determine the presence of a first analyte, and the second assay is configured to determine the presence of a second analyte different than the first analyte. 
     The first assay can be the same as the second assay. The first assay can be configured to determine the presence of a first analyte, and the second assay can be configured to determine the presence of the first analyte. 
     Performing the second assay can include subjecting the portion of the second sample in the second assay receptacle to nucleic acid amplification reaction conditions. 
     The method can also include transporting the first carrier coupled to the first processing receptacle on the host conveyor assembly such that the first carrier bypasses the second processing position within the third instrument. The method can also include transporting the second carrier coupled to the second processing receptacle on the host conveyor assembly such that the second carrier bypasses the first processing position within the second instrument. 
     The method can also include decapping at least one of the first sample containing receptacle and the first processing at a sample processing station of the first instrument, and capping the at least one of the first sample containing receptacle and the first processing at the sample processing station of the first instrument. 
     In some embodiments, an automated sample processing method includes transporting a first carrier coupled to a first processing receptacle containing a first sample from a host conveyor assembly to a first processing position within a first instrument using a first intermediate conveyor assembly. The method also includes aspirating at least a portion of the first sample from the first processing containing receptacle at the first processing position using a first automated pipettor of the first instrument. The method also includes dispensing the portion of the first sample into a first assay receptacle using the first automated pipettor of the first instrument. The method also includes performing a first assay on the portion of the first sample in the first assay receptacle using the first instrument. The method also includes transporting the first carrier from the first processing position to the host conveyor assembly using the first intermediate conveyor assembly, and transporting a second carrier coupled to a second processing receptacle containing a second sample from the host conveyor assembly to a second processing position within a second instrument using a second intermediate conveyor assembly. The method also includes aspirating at least a portion of the second sample from the second processing receptacle at the second processing position using a second automated pipettor of the second instrument, and dispensing the portion of the second sample into a second assay receptacle using the second automated pipettor of the second instrument. The method also includes performing a second assay on the portion of the second sample in the second assay receptacle using the second instrument, transporting the second carrier from the second processing position to the host conveyor assembly using the second intermediate conveyor assembly. 
     Performing the first assay can include subjecting the portion of the first sample in the first assay receptacle to nucleic acid amplification reaction conditions. 
     The first assay can be different than the second assay, or the first assay can be the same as the second assay. 
     Performing the second assay can include subjecting the portion of the second sample in the second assay receptacle to nucleic acid amplification reaction conditions. 
     The method can also include transporting the first carrier coupled to the first processing receptacle on the host conveyor assembly such that the first carrier bypasses the second processing position within the second instrument. The method can also include transporting the second carrier coupled to the second processing receptacle on the host conveyor assembly such that the second carrier bypasses the first processing position within the first instrument. 
     In some embodiments, an automated conveyor assembly transports carriers coupled to processing receptacles from (i) another conveyor assembly that transports carriers to (ii) a processing position within an instrument. The automated conveyor assembly includes a gripper configured to selectively grasp a carrier and move between (i) a first position and (ii) the processing position in the instrument. The automated conveyor assembly includes a diverter defining a recess configured to receive a carrier. The diverter being rotatable between (i) a first position at which the recess is aligned with the other conveyor assembly and (ii) a second position at which the recess is aligned with the first position of the gripper. 
     The diverter can further define a second recess aligned with the first position of the gripper when the diverter is at the first position. The second recess can be aligned with the other conveyor assembly when the diverter is at the second position. 
     The diverter can further define a third recess and is movable between the first position, the second position, and a third position at which the first recess is aligned with the other conveyor assembly, the second recess is aligned with the other conveyor assembly, and the third recess is aligned with the first position of the gripper. 
     The first recess, the second recess, and the third recess can be spaced equally about an axis about which the diverter rotates. 
     The gripper can include at least two movable prongs configured to apply pressure to the carrier grasped by the gripper. Each of the at least two movable prongs can include a portion having a protrusion configured to mate with a groove defined by the carrier grasped by the gripper such that, as a distal end of a pipettor of the instrument is removed from a respective processing receptacle of the carrier grasped by the gripper, the gripper holds the carrier to the automated conveyor assembly. Each of the at least two movable prongs can include a portion shaped to closely correspond to a respective portion of a perimeter of the carrier. Each of the at least two movable prongs can include a portion that, when the gripper is grasping the carrier, overlaps in a vertical direction at least a respective portion of the carrier. 
     The first position of the gripper can be outside the instrument. 
     The automated conveyor assembly can further include a cover that encloses a portion of a path between the first position of the gripper and the processing position in the instrument. The cover can define an opening configured to allow a distal end of a pipettor of the instrument to pass. 
     In some embodiments, a diverter transports carriers between a first automated conveyor assembly path and a second automated conveyor assembly path. The diverter includes a first recess configured to receive a first carrier and a second recess spaced apart from the first recess and configured to receive a second carrier. The diverter is rotatable between (i) a first position at which the first recess is aligned with the first automated conveyor assembly path and the second recess is aligned with the second automated conveyor assembly path, and (ii) a second position at which the first recess is aligned with the second automated conveyor assembly path and the second recess is aligned with the first automated conveyor assembly path. The diverter transport the first carrier from the first automated conveyor assembly path to the second automated conveyor assembly path while simultaneously transporting the second carrier from second automated conveyor assembly path to the first automated conveyor assembly path. 
     The first automated conveyor assembly path is perpendicular to the second automated conveyor assembly path. 
     The diverter can further include a third recess configured to receive a third carrier. At the first position of the diverter, the third recess can be aligned with the first automated conveyor assembly path, and at the second position of the diverter, the third recess can be aligned with the first automated conveyor assembly path. 
     The diverter can have a circular outer periphery defining the first recess and the second recess. The first recess can be spaced from the second recess by about 120 degrees about an axis about which the diverter rotates. 
     In some embodiments, a method of transporting carriers to a processing position within an instrument includes transporting, using an automated conveyor assembly, a carrier from a first position to the processing position within the instrument. The method also includes grasping the carrier with a gripper and inserting a distal end of an automated pipettor into a receptacle coupled to the carrier. The method also includes aspirating, using the automated pipettor, at least a portion of a sample in the receptacle, and removing the distal end of the automated pipettor from the receptacle coupled to the carrier while the gripper is grasping the carrier. 
     Transporting the carrier from the first position to the processing position can include moving the gripper while the gripper is grasping the carrier. 
     The gripper can include at least two movable prongs, and grasping the carrier with the gripper can include moving the at least two movable prongs together to apply pressure to the carrier to secure the carrier to the gripper. 
     Transporting the carrier from the first position to the processing position includes transporting the carrier using a movable track. 
     The method can also include, after removing the distal end of the automated pipettor from the receptacle coupled to the carrier, transporting the carrier from processing position within the instrument to the first position using the automated conveyor assembly. 
     The first position can be outside the instrument. 
     In some embodiments, a method of transporting carriers includes receiving a first carrier in a first recess of a diverter from a first automated conveyor assembly, and receiving in a second carrier in a second recess of the diverter from a second automated conveyor assembly. The method also includes rotating the diverter, while the first carrier is received within the first recess and the second carrier is received within the second recess, such that the first carrier is aligned with the second automated conveyor assembly and the second carrier is aligned with the first automated conveyor assembly path. The first carrier is transported from the first automated conveyor assembly to the second automated conveyor assembly simultaneously with the second carrier being transported from the second automated conveyor assembly to the first automated conveyor assembly. 
     The first automated conveyor can define a first path that is perpendicular to a second path defined by the second automated conveyor assembly path. The diverter can have a circular outer periphery defining the first recess and the second recess. The first recess can be spaced from the second recess by about 120 degrees about an axis about which the diverter rotates. 
     The method can also include transporting, after rotating the divert, the first carrier to a processing position within an instrument using the second automated conveyor assembly. Receiving the first carrier in the first recess of the diverter can occur outside the instrument. The instrument can be an assay instrument. 
     In some embodiments, a carrier for transporting a receptacle using a conveyor assembly includes a main body having a top end portion and a bottom end portion. The top end portion defines a recess configured to receive a portion of the receptacle. The carrier also includes a first groove defined in an outer periphery of the main body. The first groove is configured to mate with corresponding protrusion of the conveyor assembly as the carrier is transported by the conveyor assembly. The carrier also includes a second groove separate from the first groove and defined in the outer periphery of the main body. The second groove is configured to mate with a protrusion of a movable gripper of the conveyor assembly. The main body can be cylindrical or non-cylindrical. The recess can be cylindrical. 
     The carrier can also include a plurality of movable retaining members positioned within the recess. The retaining members define an interior recess portion configured to receive the portion of the receptacle. The plurality of movable retaining members can form an annulus that defines the interior recess portion. Each of the plurality of movable retaining members can include a tapered surface configured to self-align the portion of the receptacle with a center of the recess when the portion of the receptacle is being inserted in the interior recess portion. Each of the plurality of movable retaining members can be biased toward a center of the interior recess portion such that each retaining member applies a force to the portion of the receptacle inserted in the interior recess portion that secures the receptacle to the carrier. The carrier can also include a biasing device configured to bias each of the plurality of retaining members toward the center of the interior recess portion. The biasing device can be a garter spring, and each of the plurality of retaining members can define a periphery groove configured to receive the garter spring. Each of the plurality of movable retaining members can have a radial stroke such that the inner recess portion varies in size to accommodate receptacles of at least two different sizes. 
     The lower end portion of the main body can define a second recess configured to receive a transponder. The transponder can be an RFID tag. The second recess can include a first portion shaped to receive a first type of transponder and a second portion shaped to receive a second type of transponder different than the first type. The first portion of the second recess can be cylindrical, and the second portion of the second recess can be rectangular. A center of the first portion of the second recess and a center of the second portion of the second recess can be coaxial. 
     Further features and advantages of the embodiments, as well as the structure and operational of various embodiments, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the embodiments and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the relevant art(s) to make and use the embodiments. 
         FIG. 1  is a schematic block diagram of a laboratory automated system according to an embodiment. 
         FIG. 2  is a schematic plan view of a laboratory automated system including a sample processing instrument, a host conveyor assembly, intermediate conveyor assemblies, and assay instruments, according to an embodiment. 
         FIG. 3  is a rear view of an assay instrument and an intermediate conveyor assembly according to an embodiment. 
         FIG. 4  is a cross-sectional plan view of an assay instrument and an intermediate conveyor assembly, according to an embodiment. 
         FIG. 5  is a perspective view of a spur conveyor subassembly of an intermediate conveyor assembly, according to an embodiment. 
         FIG. 6  is a plan view of a buffer conveyor subassembly and a spur conveyor subassembly of an intermediate conveyor assembly, according to an embodiment. 
         FIG. 7  is a cross-sectional side view of an assay instrument and an intermediate conveyor assembly, according to an embodiment. 
         FIG. 8  is a perspective view of a pipettor of an assay instrument, a spur conveyor subassembly of an intermediate conveyor assembly, and a processing receptacle, according to an embodiment. 
         FIG. 9  is a perspective view of a host conveyor assembly operatively coupled to intermediate conveyor assemblies and assay instruments, according to an embodiment. 
         FIG. 10  is a perspective view of an assay instrument, an intermediate conveyor assembly, and a host conveyor assembly, according to an embodiment. 
         FIG. 11  is a schematic system diagram of a host conveyor assembly, an intermediate conveyor assembly, and an assay instrument, according to an embodiment. 
         FIG. 12  is a schematic system diagram of a host conveyor assembly, an intermediate conveyor assembly, and an assay instrument, according to another embodiment. 
         FIG. 13  is a schematic system diagram of a host conveyor assembly, an intermediate conveyor assembly, and an assay instrument, according to yet another embodiment. 
         FIG. 14  is a schematic system diagram of a sample processing instrument, a host conveyor assembly, intermediate conveyor assemblies, and assay instruments, according to an embodiment. 
         FIG. 15  is a schematic diagram of a controller of an intermediate conveyor assembly coupled to a buffer conveyor subassembly and a spur conveyor subassembly of the intermediate conveyor assembly, according to an embodiment. 
         FIG. 16  is a block diagram of a laboratory automated method, according to an embodiment. 
         FIG. 17  is a perspective view of a carrier and a receptacle according to an embodiment. 
         FIG. 18  is a cross-sectional view of the carrier and receptacle of  FIG. 17  according to an embodiment. 
         FIG. 19  is a perspective view of a capping and decapping mechanism, according to an embodiment. 
         FIG. 20  is a perspective view of a capping and decapping mechanism, according to an embodiment. 
         FIG. 21  is a perspective view of a receptacle gripper according to an embodiment. 
         FIG. 22  is a cross-sectional view of a spur conveyor subassembly of an intermediate conveyor assembly, according to an embodiment. 
         FIG. 23  is a cross-sectional view of a gripper of a spur conveyor subassembly at a subassembly at a processing position, according to an embodiment. 
         FIG. 24  is a perspective view of a diverter and a gripper (in an open configuration) of a spur conveyor subassembly, according to an embodiment. 
         FIG. 25  perspective view of a diverter and a gripper (in a closed configuration) of a spur conveyor subassembly, according to an embodiment. 
         FIG. 26  is a cross-sectional view of a carrier, a receptacle, and a gripper in a closed configuration, according to an embodiment. 
         FIG. 27  is a top perspective view of a sample carrier showing a new design. 
         FIG. 28  is a bottom perspective view thereof. 
         FIG. 29  is a front view thereof, the rear view being the same. 
         FIG. 30  is a left side view thereof, the right side view being the same. 
         FIG. 31  is a top view thereof. 
         FIG. 32  is a bottom view thereof. 
         FIG. 33  is a top perspective view of another sample carrier showing our new design. 
         FIG. 34  is a bottom perspective view thereof. 
         FIG. 35  is a top view thereof. 
         FIG. 36  is a bottom view thereof. 
         FIG. 37  is a front view of another sample carrier showing a new design, the rear, right, and left side views being the same. 
     
    
    
     The features and advantages of the embodiments will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. 
     DETAILED DESCRIPTION 
     The present disclosure will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings. References to “one embodiment,” “an embodiment,” “some embodiments,” “an exemplary embodiment,” “for example,” “an example,” “exemplary,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
     As used herein, “a” or “an” means “at least one” or “one or more.” 
     As used herein, a “sample” refers to any material to be analyzed, regardless of the source. The material may be in its native form or any stage of processing (e.g., the material may be chemically altered or it may be one or more components of a sample that have been separated and/or purified from one or more other components of the sample). A sample may be obtained from any source, including, but not limited to, an animal, environmental, food, industrial or water source. Animal samples include, but are not limited to, peripheral blood, plasma, serum, bone marrow, urine, bile, mucus, phlegm, saliva, cerebrospinal fluid, stool, biopsy tissue including lymph nodes, respiratory tissue or exudates, gastrointestinal tissue, cervical swab samples, semen or other body or cellular fluids, tissues, or secretions. Samples can be diluted or contained within a receptacle containing diluents, transport media, preservative solution, or other fluids. As such, the term “sample” is intended to encompass samples contained within a diluent, transport media, and/or preservative or other fluid intended to hold a sample. 
     As used herein, a “sample containing receptacle” refers to any type of fluid container, including, for example, a tube, vial, cuvette, cartridge, microtiter plate, etc., that contains a sample in its native form or at any stage of processing. 
     As used herein, a “processing receptacle” refers to any type of fluid container, including, for example, a tube, vial, cuvette, cartridge, microtiter plate, etc., that is configured to contain a sample at a point during processing. Exemplary processing receptacles include Aptima® collection and transport tubes (Hologic, Inc., Bedford, Mass.). 
     As used herein, an “assay receptacle” refers to any type of fluid container, including, for example, a tube, vial, cuvette, cartridge, microtiter plate, etc., that is configured to contain a sample at a point while performing an assay. In some embodiments, an assay receptacle is formed with a material that can tolerate high temperatures (e.g., between 35° C.-90° C.) without deforming or leaching chemicals into a contained sample. Exemplary processing receptacles include multiple-tube units (MTUs) that each define a plurality of cavities for receiving samples, for example, MTUs used with Panther® systems sold by Hologic, Inc., Bedford, Mass. 
     As used herein, an “assay instrument” refers to any instrument capable of analyzing a sample and rendering a result. Any instrument capable of performing a hybridization assay, a molecular assay including a nucleic acid based amplification assay, a sequencing assay, an immunoassay, or chemistry assay on a sample is included in this definition of an assay instrument. In some embodiments, an assay can be carried out directly on a sample without any sample processing, but other samples require processing before carrying out an assay. Samples requiring some form of sample processing before subjecting the samples to the steps of an assay include, in some embodiments, cell samples, tissue samples, stool samples, mucus samples, semen samples, cerebrospinal fluid samples, blood samples, bone marrow samples, serum samples, urine samples, bile samples, respiratory samples, sputum samples, and exosome samples, among others. Exemplary assay instruments include the Tigris® and Panther® systems sold by Hologic, Inc., Bedford, Mass. 
     As used herein, a “sample processing instrument” refers to an instrument capable of performing a processing step on a sample contained within a receptacle before performing an assay on the sample, and is not capable of analyzing a sample and/or rendering a result. For example, an instrument that transfers a sample from one receptacle to another receptacle, but does not perform an assay on the sample, is a sample processing instrument. An exemplary sample processing instrument is the Tomcat® system sold by Hologic, Inc., Bedford, Mass. 
     As used herein, a “robotic arm” refers to an electromechanical device that translates a payload (e.g., a pipettor, a receptacle gripper (such as a pick-and-place claw), a camera, a sensor, a capper/decapper, etc.) in the X, Y, and/or Z directions. In an embodiment, a robotic arm can move in the X, Y, and Z directions. 
     1. Exemplary Embodiments of Laboratory Automated Systems 
       FIG. 1  schematically illustrates a laboratory automated system  100  according to an embodiment. System  100  includes a host conveyor assembly  102  configured to transport a plurality of carriers and receptacles coupled thereto (described further below) between at least one sample processing instrument  104  (for example, one sample processing instrument  104  as shown in  FIG. 1 , or two or more sample processing instruments  104 ) and at least one assay instrument (for example, three assay instruments  108   a ,  108   b , and  108   c  as shown in  FIG. 1 , collectively referred to as assay instruments  108  or individually and generically as assay instrument  108 ). In other embodiments, system  100  includes more than one sample processing instrument  104  and more than or less than three assay instruments  108 . 
     System  100  can also include an intermediate conveyor assembly  106  configured to transport a plurality of carriers and receptacles coupled thereto from within sample processing instrument  104  to host conveyor assembly  102 . In some embodiments, intermediate conveyor assembly  106  is also configured to transport a plurality of carriers from host conveyor assembly  102  to within sample processing instrument  104 . 
     System  100  also includes an intermediate conveyor assembly for each of assay instruments  108  (for example, intermediate conveyor assemblies  133   a ,  133   b , and  133   c , collectively referred to as intermediate conveyor assemblies  133  or generically and individually as intermediate conveyor assembly  133 ). Intermediate conveyor assemblies  133  are configured to transport a plurality of carriers from host conveyor assembly  102  to respective processing positions within respective assay instrument  108   a ,  108   b , and  108   c.    
     In some embodiments, intermediate assay conveyor assemblies  133  each include a buffer conveyor assembly (buffer conveyor subassemblies  114   a ,  114   b , and  114   c  as shown in  FIG. 1 , collectively referred to as buffer conveyor subassemblies  114  or generically and individually as buffer subassembly  114 ) and a spur conveyor assembly (spur conveyor subassemblies  116   a ,  116   b , and  116   c  in  FIGS. 1 and 2 , collectively referred to as spur conveyor subassemblies  116  or generically and individually referred to as spur subassembly  116 ). Each buffer conveyor subassembly  114  is configured to receive carriers from host conveyor assembly  102  and transport the carriers to an intermediate position upstream from the processing position of the respective assay instrument  108 . Spur conveyor subassembly  116  is configured to receive a carrier from buffer conveyor subassembly  114  and transport the carrier to the processing position of the respective assay instrument  108 . The respective assay instrument  108  can process a sample contained within a receptacle coupled to the carrier at the processing position as explained further below. Spur conveyor subassembly  116  is also configured to transport the carrier from the processing position back to buffer conveyor subassembly  114 . Buffer conveyor subassembly  114  is also configured to transport the carriers received from spur conveyor subassembly  116  back to host conveyor assembly  102 . 
     After receiving carriers from a buffer conveyor subassembly of one intermediate conveyor assembly, host conveyor assembly  102  transport the carriers to other position within system  100 , for example, to another assay instrument  108 , to another sample processing instrument  104 , or to any other instrument operatively coupled to host conveyor assembly  102 . 
       FIG. 2  illustrates a schematic plan view of system  100  according to an embodiment. As shown in  FIG. 2 , system  100  includes one sample processing instrument  104 , an intermediate conveyor assembly  106 , a host conveyor assembly  102 , three intermediate conveyor assemblies  133   a - 133   c , and three assay instruments  108   a - 108   c . In other embodiments, system  100  can include more than one sample processing instrument  104 , or system  100  can omit sample processing instrument  104 . In other embodiments, system  100  can include less than three or more than three assay instruments  108 , or system  100  can omit assay instruments  108 . Embodiments of each of these components of system  100  are described further below. 
     A. Exemplary Embodiments of Sample Processing Instruments  104   
     In some embodiments, sample processing instrument  104  is an instrument according to any one of the embodiments described in U.S. Patent Application Publication No. 2013/0065797, published on Mar. 14, 2013. For example, sample processing instrument  104  can include a sample processing station  107 , an input bay  109  configured to movably and manually receive one or more input racks  111 , an output bay  113  configured to movably receive one or more output racks  115 , one or more robotic arms  117 , one or more receptacle grippers  119 , one or more pipettors  121 , one or more incubators  123 , and a controller. In some embodiments, receptacle gripper  119  is coupled to robotic arm  117  and configured to transport sample containing receptacles  105  and processing receptacles  103  within sample processing instrument  104 , for example, between input racks  111 , a sample processing station  107 , output racks  115 , and intermediate conveyor assembly  106 . Each of these components of sample processing instrument  104  can be enclosed by an instrument housing. Sample containing receptacles  105  contain a sample, for example, an animal sample such as a liquid based cytology (LBC) specimen. 
     In some embodiments, processing receptacles  103  within instrument  104  are configured to be used in at least one of assay instruments  108 . 
     In some embodiments, sample pipettor  121  is configured to transfer samples from sample containing receptacles  105  (e.g., liquid based cytology (LBC) specimen collection containers), to processing receptacles  103  (e.g., Aptima® collection and transport tubes available from Hologic, Inc., Bedford, Mass.). 
     In some embodiments, sample processing station  107  is configured to hold sample containing receptacles  105  and processing receptacles  103 , perform barcode reading, barcode positioning, sample mixing, and capping/decapping of sample containing receptacles  105  and processing receptacles  103 . In some embodiments, sample processing station  107  includes a capping/decapping mechanism configured to cap and decap receptacles, for example, sample containing receptacles  105  or processing receptacles  103 .  FIGS. 19 and 20  illustrate a capping/decapping mechanism  201  according to an embodiment. Capping/decapping mechanism  201  can be configured to cap and decap two or more different types of containers having a different shape and/or different shaped cap. Capping/decapping mechanism  201  can include a chuck  203  that is configured to selectively grasp a cap of a receptacle, for example, a sample containing receptacle  105  or a processing receptacle  103 . As shown in  FIGS. 19 and 20 , chuck  203  can include a plurality of prongs that are configured to move radially inward to grasp a cap of either a sample containing receptacle  105  or a processing receptacle  103 , and radially outward to release the cap. In some embodiments, capping/decapping mechanism  201  rotates to rotate the grasped cap relative to the main body of a sample containing receptacle  105  or a processing receptacle  103 , thereby capping or decapping a sample containing receptacle  105  or a processing receptacle  103 . In other embodiments, capping/decapping mechanism  201 , while grasping the cap, remains stationary, and sample processing station  107  rotates the main body of a sample containing receptacle  105  or a processing receptacle  103  relative to the grasped cap thereby capping or decapping a sample containing receptacle  105  or a processing receptacle  103 . 
     In some embodiments, sample processing instrument  104  includes one or more incubators  123 . Incubators  123  can be configured to incubate samples directly within processing receptacles  103 . For example, LBC samples such as biological samples collected in a SurePath® (Becton Dickinson, Inc., Franklin Lakes, N.J.) sample containing receptacle  105  often require processing, such as reagent addition and heated incubation using incubators  123 , before conducting a molecular assay. In other embodiments, LBC sample types such as those collected in a ThinPrep® (Hologic, Inc., Bedford, Mass.) sample containing receptacle may not require further processing such as incubation using incubators  123 . 
     In some embodiments, sample processing instrument  104  also includes a controller that is configured to manage and process device-wide activities by delegating specific tasks to instrument sub-components or modules. Exemplary system activities include capping/decapping collection and processing receptacles, vortexing, moving collection and processing receptacles, pipetting, waste reservoir monitoring, monitoring consumable inventory, monitoring sample queues, maintaining run logs, monitoring process controls, monitoring system alarms, etc. 
     In some embodiments, sample processing instrument  104  includes a software user interface. In one embodiment, the user interface incorporates an integrated touch screen for operator input, instrument control, status monitoring, and displaying sample tracking information. In some embodiments, sample processing instrument  104  includes data input devices. For example, sample processing instrument  104  can include USB ports, for example, for updating system configuration files, downloading sample tracking data and run logs, and connecting additional user interface devices such as a mouse or keyboard. 
     In some embodiments, sample processing instrument  104  includes a hardware user interface so that a user can access various areas of sample processing instrument  104 , for example, the sample input bay  109 , the output bay  113 , and the consumable areas. In one embodiment, sample processing instrument  104  includes two or more cabinets or drawers on the front of the automated instrument to access these areas. 
     Sample processing instrument  104  can also include output bay  113  configured to movably receive, for example, slidably receive, and hold one or more output racks  115 . The output racks can act as input queues for assay instruments not coupled to host conveyor assembly  102 . 
     Sample processing instrument  104  can also include input bay  109  that is configured to movably receive, for example, slidably receive, and hold one or more input racks  111 . 
     In some embodiments, sample processing instrument  104  is configured to handle a variety of sample types, including samples collected in different shaped collection receptacles. In one such embodiment, input bay  109  is configured to hold multiple types of sample input racks  111 . For example, in one embodiment, input bay  109  is configured to hold sample input racks  111  containing ThinPrep® and/or SurePath® sample containing receptacles  105 , respectively. In another embodiment, each sample input rack  111  is configured to hold a single type of specimen such that if two input racks  111  are in input bay  109 , one input rack  111  may contain only ThinPrep® sample containing receptacles  105 , and the other input rack may contain only SurePath® sample containing receptacles  105 . In another embodiment, each input rack  111  received within input bay  109  of sample processing instrument  104  is configured to hold two or more different shaped receptacles  105 . For example, each input rack can be configured to hold two or more different shaped sample containing receptacles  105 , for example, ThinPrep® and SurePath® sample containing receptacles  105 , respectively. In such embodiments, the input rack  111  can be configured to hold SurePath® sample containing receptacles  105  (including the corresponding processing receptacles  103  in some embodiments) on one side, and ThinPrep® sample containing receptacles  105  (including the corresponding processing receptacles  103  in some embodiments) on the opposite side. In use, such a input rack  111  can hold SurePath® sample containing receptacles  105 , and then if flipped upside down, the same input rack  111  can hold ThinPrep® sample containing receptacles  105 . In some embodiments, processing receptacles  103  held by the input rack  111  in input bay  109  do not contain a sample. In some embodiments, each input rack received within input bay  109  of sample processing instrument  104  is configured to hold both a sample containing receptacle  105  and a processing receptacle  103  that is configured differently than the sample containing receptacle  105 . In such embodiments, input rack  111  can be configured to hold multiple pairs of sample containing receptacles  105  and processing receptacles  103 , such that sample containing receptacles  105  and processing receptacles  103  are incorporated in a one-to-one ratio and in an alternating fashion as shown in  FIG. 1 . In such embodiments, the user, after verifying instrument consumable levels, can begin sample processing by simply inserting input rack  111  holding pairs of sample containing receptacles  105  and processing receptacles  103  into input bay  109  of the automated instrument  104 . 
     In some embodiments, receptacle gripper  119  and robotic arm  117  of processing instrument  104  are configured to couple receptacles  103  with respective carriers  101 . And in some embodiments, receptacle gripper  119  and robotic arm  117  are configured to place receptacles  103  and the corresponding coupled carriers  101  onto intermediate conveyor assembly  106 . 
     In some embodiments, receptacle gripper  119  and robotic arm  117  are configured to place receptacles  103  onto output racks  115 . Once processing receptacles  103  are placed on output rack  115 , a user can retrieve output rack  115  to run assay(s) on the contents of the processing receptacles  103  using an assay instrument (coupled or uncoupled to host conveyor assembly  102 ). In some embodiments, output rack  115  is configured to be operable in an assay instrument  108  that performs the assay, for example, an assay instrument configured to perform molecular assays. For example, in some embodiments, output rack  115  of processing instrument  104  functions as an input rack for an assay instrument  108 . In such embodiments, the user removes rack  115  holding processed samples in processing receptacles  103  from the automated processing instrument  104 , and inserts rack  115  in the input bay of an automated assay instrument  108 , for example, a molecular assay instrument that performs a desired assay. In other embodiments, processing receptacles  103  in output rack  115  are manually transferred to an input rack configured to be operable in an automated assay instrument  108 , for example, a molecular assay instrument that performs a desired assay. 
     In some embodiments, processing instrument  104  places matching machine readable labels (such as barcodes) on both a paired sample containing receptacle  105  and processing receptacle  103 . In some embodiments, sample processing instrument  104  includes an onboard barcode reader  127  configured to read barcodes on sample containing receptacle  105  or processing receptacle  103  placed in sample processing station  107 . 
     In some embodiments, sample processing instrument  104  includes one or more robotic arms  117  configured to translate in the X, Y, and Z planes within the automated instrument. In some embodiments, one robotic arm includes receptacle gripper  119  and is configured to transport sample containing receptacles  105  and processing receptacles  103  within sample processing instrument  104 , for example, between input racks  111 , sample processing station  107 , output racks  115 , and intermediate conveyor assembly  106 . For example, sample processing instrument  104  can include one robotic arm  117  and one receptacle gripper  119  configured to transport sample containing receptacles  105  and processing receptacles  103 . In other embodiments, sample processing instrument  104  includes more than one robotic arm  117  and more than one receptacle gripper  119  configured to transport sample containing receptacles  105  and processing receptacles  103  within the housing of instrument  104 . In some embodiments, robotic arm  117  is any one of the robotic arm embodiments described in U.S. application Ser. No. 13/608,876, filed Sep. 10, 2012. 
     In some embodiments, robotic arm  117 , which includes gripper  119 , also includes a pipettor  121  configured to aspirate and dispense sample material. In some embodiments, pipettor  121  is an air-based pipettor configured to aspirate a sample from sample containing receptacles  105  or a reagent from a reagent containing receptacle and dispense the sample or reagent into a processing receptacle  103 . 
     In some embodiments, processing instrument  104  includes at least two separate robotic arms  117 . One robotic arm  117  can include pipettor  121  for transferring samples, and the other robotic arm  117  can include gripper  119  for transporting sample containing receptacles  105  and processing receptacles  103 . 
     In some embodiments, receptacle gripper  130  is configured to pick-and-place sample containing receptacles  105  and processing receptacles  103  within sample processing instrument  104 . 
     In some embodiments, samples are transferred from sample containing receptacles  105  to processing receptacles  103  in a serial fashion. For example, pipettor  121  is configured to take an aliquot of a sample from one sample containing receptacle  105  and transfer the aliquot to a processing receptacle  103 . Thereafter pipettor  121  is configured to take another aliquot of a different sample from a different sample containing receptacle  105  and transfer the aliquot to another, different processing receptacle  103 . An exemplary process for transferring and processing the sample, for example, at sample processing station  107 , is described in detail below. 
     In some embodiments, sample processing instrument  104  is configured to add a reagent to a sample and/or incubate the sample as part of the sample processing. 
     In some embodiments, a receptacle gripper  119  of robotic arm  117  will transport processing receptacles  103  to incubator  123 , for example, after completion of processing in sample processing station  107 . After incubation is complete, receptacle gripper  119  of robotic arm  117  will transport processing receptacles  103  from incubator  123  to a carrier  101  positioned within instrument  104  or to an output rack  115 . 
     In some embodiments, receptacle gripper  119  performs all pick and place duties required by sample processing instrument  104 . In some embodiments, receptacle gripper  119  is programmed, by way of the controller, to perform one or more of the following steps: (1) transport processing receptacles  103  and sample containing receptacles  105  between, for example, input racks  111  and sample processing station  107 , (2) transport sample containing receptacles  105  from sample processing station  107  to input racks  111 , (3) transport processing receptacles  103  from processing station  107  to incubator  123 , (4) transport processing receptacles  103  from processing station  107  to be coupled with carriers  101 , and (5) transport processing receptacles  103  from the one or more incubators  123  to be coupled with carriers  101 . In some embodiments, sample processing instrument  104  uses multiple receptacle grippers  117  to perform the above steps, which can maximize throughput and permits uninterrupted processing in sample processing station  107 . 
       FIG. 21  illustrates a receptacle gripper  119  of robotic arm  117  of processing instrument  104  according to one embodiment. As shown in  FIG. 21 , receptacle gripper  119  includes a chuck  302  that is configured to selectively grasp a portion, for example a cap, of a sample containing receptacle  105  or a processing receptacle  103 . Chuck  302  can include a plurality of prongs  304  (for example, three prongs  304  as shown in  FIG. 21 ) that are configured to move radially inward to grasp a cap of either a sample containing receptacle  105  or a processing receptacle  103 , and radially outward to release the sample containing receptacle  105  or a processing receptacle  103 . 
     Ensuring sample identification accuracy is another problem encountered when automating a sample processing process. For example, as the sample is prepared it is transferred between a sample containing receptacle  105  and a processing receptacle  103 . Therefore, it is important to ensure that the sample in processing receptacle  103  is correlated with the sample in sample containing receptacle  105  so that the sample is processed according to the proper protocol and that the correlation of that sample with the donor patient is maintained. Accordingly, in some embodiments, system  100  tracks the identification of each sample throughout processing, including processing within instrument  104 , following the sample as it is transferred from sample containing receptacle  105  to processing receptacle  103  and subsequent handling by host conveyor assembly  102  and processing by one or more assay instruments  108 . One exemplary method of tracking this information within system  100 , including within instrument  104 , is to utilize matching barcodes on both sample containing receptacle  105  and processing receptacle  103 . This process maintains sample-to-result positive identification tracking. In some embodiments, a user, for example, a laboratory, prints one barcode containing patient identification and applies it to sample containing receptacle  105 . Processing receptacle  103 , in turn, contains no label, a blank label, or a different label. Sample processing instrument  104 , for example, using barcode reader  127 , then reads the barcode of sample containing receptacle  105 , transfers (for example, using a writer  131 ) information from the read barcode, for example, an identifier, to at least one of processing receptacle  103  or the corresponding carrier  101  coupled to the processing receptacle  103 . 
     In some embodiments, writer  131  is a printer that prints the same barcode as contained on sample containing receptacle  105  (with optional additional metadata in the form of barcode prefixes, suffixes, or similar metadata) and applies the barcode to processing receptacle  103  and/or carrier  101 . In some embodiments, the printer is any one of the printer embodiments described in U.S. application Ser. No. 14/919,467, filed Oct. 21, 2015. In some embodiments, sample processing instrument  104  reads the barcode of sample containing receptacle  105 , and writer  131  creates the same barcode (with optional additional metadata in the form of barcode prefixes, suffixes, or similar metadata) directly on processing receptacle  103  and/or carrier  101 , for example, by way of printing, imprint, burning, thermal transfer, or another method. Also in some embodiments, a different bar code is printed on processing receptacle  103  or carrier  101  containing additional metadata (e.g., time, volume, type, reagents, errors, etc.) related to the processing of the corresponding sample. 
     In some embodiments, writer  131  is an RFID writer configured to transfer information, including for example, an identifier, to an RFID tag on processing receptacle  103 , carrier  101 , or both. In such embodiments, the RFID tag on processing receptacle  103  or carrier  101  can be passive (e.g., a microchip attached to an antenna) or active (e.g., active transponders or beacons) RFID tags. Exemplary passive RFID tags can operate at low, high, or ultra-high frequency. Low frequency passive RFID tags can operate, for example, at 124 kHz, 125 kHz, or 135 kHz. High frequency passive RFID tags can operate, for example, at 13.56 MHz. And ultra-high frequency passive RFID tags can operate, for example, at a range from 860 MHz to 960 MHz. In some embodiments, the passive RFID tag operates at 2.45 GHz. In some embodiments, RFID writer  131  transfers information obtained from the barcode on sample containing receptacle  105  (with optional additional metadata in the form of barcode prefixes, suffixes, or similar metadata) to the RFID tag on receptacle  103  and/or carrier  101 . Also in some embodiments, RFID writer  131  transfers information different than information found on the barcode on sample containing receptacle  105  (e.g., time, volume, type, reagents, errors, etc.) related to the processing of the corresponding sample within instrument  104 . 
     In some embodiments, writer  131  includes both an RFID writer module and a printer module as described above. 
     In some embodiments, instrument  104  does not include writer  131 . Instead, instrument  104  includes an RFID reader configured to read information, for example, an identifier, from an RFID tag on either carrier  101  or processing receptacle  103 . Automated sample processing instrument  104  reads both the barcode on sample containing receptacle  105  creates an association between (1) the sample containing receptacle  105  from which a sample was taken and (2) the read identifier of the RFID tag on the carrier  101  or receptacle  103  in which a portion of the sample was dispensed. This association information is then transferred to a laboratory information system via a network connection (e.g., LAN, Ethernet, WiFi, Bluetooth®, ZigBee®, RS232, USB, RF, IR, Firewire®, Thunderbolt®, eSATA, or other network connection). 
     As explained below, when system  100  encounters carriers  101  and processing receptacles  103  with information, for example, an identifier, associated with various positions within system  100 , system  100  handles carriers  101  and processes receptacles  103  accordingly. 
     In some embodiment, receptacle gripper  119  retrieves sample containing receptacle  105  and processing receptacle  103  from input rack  111 . Both receptacles  103  and  105  are transported to sample processing station  107  where, for example, the barcodes of receptacles  103  or  105  passed through a field of view of barcode reader  127  to be read and verified to be a corresponding pair. In such an embodiment, processing receptacle  103  can be transported to the writer  131 , for example, a printer or RFID writer, by receptacle gripper  119  of robotic arm  117  to print a barcode or transfer information to an RFID tag on processing receptacle  103  before receptacle  103  is transported to sample processing station  107 . The barcode printed on, or otherwise applied, or information transferred to processing receptacle  103  may be identical to the information on the barcode on corresponding sample containing receptacle  105 , or it may be a different barcode. In some embodiments, a different bar code is printed on or different information is transferred to processing receptacle  103  that encodes additional metadata relevant to the processing of that particular sample. 
     In some embodiment, once processing has been completed, gripper  119  of robotic arm  117  transports processing receptacle  103  to a carrier  101 , and transports sample containing receptacle  105  back to input rack  111 . For example, if carrier  101  is a puck defining a recess, gripper  119  can insert a portion of processing receptacle  103  into the recess defined by the carrier  101 , thereby coupling processing receptacle  103  to carrier  101 . Then in some embodiments, gripper  119  or another device (e.g., another robotic arm or conveyor assembly) transports receptacle  103  and the respective carrier  101  to intermediate conveyor assembly  106 . 
     In some embodiments, the automated processing instrument  104  is a high-throughput, random access sample processing instrument  104  capable of simultaneously processing multiple different sample types. As indicated, the instrument automatically processes samples according to a rule set that balances throughput with time-to-next-result, which is particularly relevant when the instrument is processing different types of samples that require different routines and reagents. For example, in one embodiment, instrument  104  is designed to process up to about 540 samples that do not require incubation, or up to about 360 samples that require reagent addition and heated incubation within a single eight hour shift. Included in this time is instrument setup, run preparation, sample processing, clean up and instrument power down. For purposes of this discussion, a “run” is defined as the processing of up to about sixty samples, for example, LCB specimens, from start to finish. In other embodiments, a run can include processing more or less than sixty samples, depending on the number of available input lanes in the input bay  109  and output lanes in the output bay of the machine. For example, a run could refer to the processing of up to about ninety-six samples, for example, LCB specimens, from start to finish. In one embodiment, a run refers to processing a collection of samples that occupy a defined portion or all of the available input lanes of the input bay  109  or that occupy a defined portion or all of the available output lanes of the output bay. 
     In some embodiments, instrument  104  is configured to perform one or more of the following processes (for example, when processing a ThinPrep® sample): 
     1. Using robotic arm  117  having receptacle gripper  119 , pick sample containing receptacle  105  from input rack  111  and place in a corresponding container holster on a carousel in processing station  107 ;
 
2. Read a barcode on sample containing receptacle  105  using barcode reader  127 ;
 
3. Orbital mix the sample in sample containing receptacle  105  using processing station  107 ;
 
4. If necessary, using robotic arm  117  having receptacle gripper  119 , pick corresponding processing receptacle  103  from input rack  111  and place in the printer for printing a barcode (or other machine readable label) on processing receptacle  103 ;
 
5. Using robotic arm  117  having receptacle gripper  119 , pick corresponding processing receptacle  103  from the printer and place in a processing receptacle holster on a carousel in processing station  107 ;
 
6. Uncap the sample containing receptacle  105  using a capping/decapping mechanism  201  at the sample processing station  107 ;
 
7. Using pipettor  121 , aspirate at least a portion of a sample from sample containing receptacle  105 ;
 
8. Recap sample containing receptacle  105  using a capping/decapping mechanism  201 ;
 
9. Uncap the processing receptacle  103  using a capping/decapping mechanism  201  at the sample processing station  107 ;
 
10. Using pipettor  121 , dispense the aspirated portion of the sample into processing receptacle  103 ;
 
11. Recap the processing receptacle  103  using the capping/decapping mechanism  201  at the sample processing station  107 ;
 
12. Using robotic arm  117  with receptacle gripper  119 , transport sample containing receptacle  105  to input rack  111 ;
 
13. Using robotic arm  117  with receptacle gripper  119 , couple processing receptacle  103  with a carrier  101  (for example, by inserting a portion of processing receptacle  103  within a recess defined by carrier  101 ); and
 
14. Using robotic arm  117  with receptacle gripper  119 , transport processing receptacle  103  coupled to carrier  101  to intermediate conveyor assembly  106 .
 
15. Alternatively, using robotic arm  117  with receptacle gripper  119 , transport processing receptacle  103  to output rack  115 .
 
     In some embodiments, processing instrument  104  is configured to perform one or more of the following processes (for example, when processing a SurePath® sample): 
     1. Using robotic arm  117  having receptacle gripper  119 , pick sample containing receptacle  105  from input rack  111  and place in a corresponding container holster on a carousel in processing station  107 ;
 
2. Read a barcode on sample containing receptacle  105  using barcode reader  127 ;
 
3. Orbital mix the sample in sample containing receptacle  105  using processing station  107 ;
 
4. If necessary, using robotic arm  117  having receptacle gripper  119 , pick corresponding processing receptacle  103  from input rack  111  and place in the printer for printing a barcode (or other machine readable label) on processing receptacle  103 ;
 
5. Using robotic arm  117  having receptacle gripper  119 , pick corresponding processing receptacle  103  from the printer and place in a processing receptacle holster on a carousel in processing station  107 ;
 
6. Uncap the sample containing receptacle  105  using a capping/decapping mechanism  201  at the sample processing station  107 ;
 
7. Using pipettor  121 , aspirate a predetermined amount of a sample processing reagent (e.g., Fast Express reagent, available from Hologic, Inc., Bedford, Mass.) from a reagent containing receptacle within instrument  104 ;
 
8. Using pipettor  121 , aspirate at least a portion of a sample from sample containing receptacle  105 ;
 
9. Recap sample containing receptacle  105  using a capping/decapping mechanism  201 ;
 
10. Uncap the processing receptacle  103  using a capping/decapping mechanism  201  at the sample processing station  107 ;
 
11. Using pipettor  121 , dispense the aspirated portion of the sample into processing receptacle  103 ;
 
12. Recap the processing receptacle  103  using the capping/decapping mechanism  201  at the sample processing station  107 ;
 
13. Using robotic arm  117  with receptacle gripper  119 , transport sample containing receptacle  105  to input rack  111 ;
 
14. Optionally, mixing processing receptacle  103 ;
 
15. Using robotic arm  117  with receptacle gripper  119 , transport processing receptacle  103  to output rack  115 , or incubator  123  for incubation;
 
16. If processing receptacle  103  is positioned in incubator  123 , using robotic arm  117  with receptacle gripper  119 , either transport processing receptacle  103  from incubator  123  to output rack  115  after incubation or couple processing receptacle  103  with a carrier  101  (for example, by inserting a portion of processing receptacle  103  within a recess defined by carrier  101 ); and
 
16. If receptacle  103  is coupled to carrier  101 , using robotic arm  117  with receptacle gripper  119 , transport processing receptacle  103  coupled to carrier  101  to intermediate conveyor assembly  106 .
 
     In some embodiments, one or more of the above processes can occur simultaneously. The above automated protocols are provided by way of example only such that modifications of the number of steps, what happens in each step, and the number of processes occurring in a particular order or simultaneously may be changed or altered without affecting the subject matter of this disclosure. One of skill in the art would appreciate that the processing time required to process each sample has a direct effect on the number of samples that can be prepared in a given time period. Manipulation of the processing time may have a detrimental impact on processing accuracy and can increase the risk of contamination, though a variety of sample processing times are contemplated with the caveat that downtime between sample processing is kept to a minimum. 
     B. Exemplary Embodiments of Intermediate Conveyor Assembly  106   
     As shown in  FIG. 2 , intermediate conveyor assembly  106  is configured to transport a plurality of carriers  101  from a position  136  to a position  135 . In some embodiments, position  136  is within a housing of sample processing instrument  104 , and position  135  is outside the housing of processing instrument  104 . Intermediate conveyor assembly  106  is configured to transport carriers  101  that are each coupled a processing receptacle  103 . In some embodiments, processing receptacles  103  coupled to carriers  101  each contain a sample portion dispensed by an automated pipettor  121  of sample processing instrument  104  and processed according to any one of the above identified processes of sample processing instrument  104 . 
     In some embodiments, intermediate conveyor assembly  106  defines a single path along which carriers  101  move as shown in  FIG. 2 . In other embodiments, intermediate conveyor assembly  106  defines two or more paths along which carriers  101  move. In some embodiments, intermediate conveyor assembly  106  includes a movable track that defines the path along which carriers  101  move. In some track embodiments, the track can be a unitary belt or a plurality of links coupled to form a belt. In such track embodiments, carriers  101  sit on the track(s) and move as the track(s) move, for example, in the direction of the annotated arrow in  FIG. 2 . In other embodiments (not shown), intermediate conveyor assembly  106  includes a movable gripper that defines the path along which carriers  101  move. For example, the gripper can grasp a carrier  101  or a processing receptacle  103  coupled to carrier  101  and move in the direction of the annotated arrow in  FIG. 2 . 
     Intermediate conveyor assembly  106  is configured to transfer carriers  101  to host conveyor assembly  102 . For example, in some embodiments, intermediate conveyor assembly  106  includes a diverter  140  configured to transfer a carrier  101  located at position  135  to host conveyor assembly  102 . In some embodiments, diverter  140  is a rotatable disc that defines one or more recesses (for example, three recesses as shown in  FIG. 2 ) configured to receive a carrier  101  at position  135 . As diverter  140  rotates, carrier  101  received within the recess defined by diverter  140  is transferred to host conveyor assembly  102 . In some embodiments, diverter  140  is configured to rotate in one direction or in two directions about an axis of rotation. 
     C. Exemplary Embodiments of Host Conveyor Assembly  102   
     Host conveyor assembly  102  is configured to transport a plurality of carriers  101  along a path. In some embodiments, this path transports carriers  101  between positions adjacent processing instrument  104  and assay instruments  108   a - 108   c . The path defined by host conveyor assembly  102  can have various shapes based on the placement of processing instrument  104  and assay instruments  108   a - 108   c . For example, as shown in  FIG. 2 , the path defined by host conveyor assembly  102  is substantially rectangular. But in other embodiments, the path defined by host conveyor assembly  102  can have non-rectangular shapes such as an L-shape or a circular shape. As shown in  FIG. 2 , host conveyor assembly  102  includes a first portion  118  configured to transport carriers  101  in a first direction as indicated by the annotated arrows, and a second portion  120  configured to transport carriers  101  in a second direction, opposite the direction of first portion  118 , as indicated by the annotated arrows pointing in the opposite direction. In some embodiments, first portion  118  and second portion  120  are linear as shown in  FIG. 2 . 
     In some embodiments, the first portion  118  includes one or more movable tracks that define the path along which carriers  101  move in the first direction. In some embodiments, the first portion  118  includes a single track that defines the path along which carriers  101  move. In some track embodiments, the track(s) of first portion  118  can be unitary belts or a plurality of links coupled to form one or more belts. In such track embodiments, carriers  101  sit on the track(s) of first portion  118  and move as the track(s) move. In other embodiments, host conveyor assembly  102  includes a movable gripper that defines the path along which carriers  101  move along first portion  118 . 
     In some embodiments, the second portion  120  includes one or more movable tracks that define the path along which carriers  101  move in the first direction. In some embodiments, the second portion  120  includes a single track that defines the path along which carriers  101  move. In some track embodiments, the track(s) of second portion  120  can be unitary belts or a plurality of links coupled to form one or more belts. In such track embodiments, carriers  101  sit on the track(s) of second portion  120  and move as the track(s) move. In other embodiments, host conveyor assembly  102  includes a movable gripper that defines the path along which carriers  101  move along second portion  120 . 
     Host conveyor assembly  102  can include one or more drive assemblies (not shown in  FIG. 2 ) configured to move the drive elements (for example, movable tracks or grippers) of first and second portions  118  and  120  of host conveyor assembly  102 . In some embodiments, a single drive assembly moves both the drive elements of first and second portions  118  and  120  of host conveyor assembly  102 . 
     In some embodiments, host conveyor includes a diverter  122  configured to transfer carriers  101  from first portion  118  to second portion  120 . In some embodiments, diverter  122  is a rotatable disc that defines one or more recesses (for example, one recess as shown in  FIG. 2 ) configured to receive a carrier  101  on the first portion  118  of host conveyor assembly  102 . As diverter  122  rotates, the carrier  101  received within the recess defined by diverter  122  is transferred to second portion  120  of host conveyor assembly  102 . In some embodiments, diverter  140  is configured to rotate in one direction or in two directions about an axis of rotation. In some embodiments, host conveyor assembly  102  includes a sensor  126  configured to detect the presence of a carrier  101  at a position in which the carrier  101  is received within the recess of diverter  122 . In some embodiments, diverter  122  is operably coupled to sensor  126  such that when a carrier  101  is detected to be within the recess defined by diverter  122 , rotation of diverter  122  is actuated and the carrier  101  is transferred to second portion  120  of host conveyor assembly  102 . In some embodiments, diverter  122  is located at a terminal end portion of first portion  118 , and at a beginning end portion of second portion  120 . In other embodiments, diverter  122  is positioned at non-terminal or beginning ends of first and second portions  118  and  120  of host conveyor assembly  102 . 
     In some embodiments, host conveyor assembly  102  includes another diverter  124  configured to transfer carriers  101  from second portion  120  to first portion  118 . In some embodiments, diverter  124  is a rotatable disc that defines one or more recesses (for example, one recess as shown in  FIG. 2 ) configured to receive a carrier  101  on the second portion  120  of host conveyor assembly  102 . As diverter  124  rotates, the carrier  101  received within the recess defined by diverter  124  is transferred to first portion  118  of host conveyor assembly  102 . In some embodiments, diverter  124  is configured to rotate in one direction or in two directions about an axis of rotation. In some embodiments, host conveyor assembly  102  includes a sensor  128  configured to detect the presence of a carrier  101  at a position in which the carrier  101  is received within the recess of diverter  124 . In some embodiments, diverter  124  is operably coupled to sensor  128  such that when a carrier  101  is detected to be within the recess defined by diverter  122 , rotation of diverter  124  is actuated and carrier  101  is transferred to first portion  118  of host conveyor assembly  102 . In some embodiments, diverter  124  is located at a terminal end portion of second portion  120 , and at a beginning end portion of first portion  118  of host conveyor assembly  102 . In other embodiments, diverter  124  is positioned at non-terminal or beginning ends of second and first portions  120  and  118  of host conveyor assembly  102 . 
     In some embodiments, one or more of assay instruments  108  and intermediate assay conveyor assemblies  133  are operatively coupled to first portion  118  of host conveyor assembly  102  (assay instruments  108   a  and  108   b , and intermediate conveyor assemblies  133   a  and  133   b  as shown in  FIG. 2 ), and one or more assay instruments  108  and respective intermediate conveyor assemblies  133  (assay instrument  108   c  and intermediate conveyor assembly  133   c  as shown in  FIG. 2 ) are operative coupled to second portion  120  of host conveyor assembly  102 , as shown in  FIG. 2 . In other embodiments (not shown in  FIG. 2 ), none of assay instruments  108  and respective intermediate conveyor assemblies  133  are coupled to one of first and second portions  118  and  120  of host conveyor assembly  102 . 
     In some embodiments, host conveyor assembly  102  is configured to transport carriers  101  to positions (for example, positions  141   a ,  141   b , and  141   c  as shown in  FIG. 2 , collectively referred to as positions  141  or generically and individually as position  141 ) outside and adjacent respective assay instruments  108 . In other embodiments (not shown), position  141  is inside the housing of respective assay instrument  108 . 
     In some embodiments, at position  141 , host conveyor assembly  102  is configured to transport a carrier  101  such that carrier  101  either bypasses respective assay instrument  108  or is transported to intermediate conveyor assembly  133 . For example, referring to  FIG. 2 , host conveyor assembly  102  can be configured to transport a carrier  101  such that it bypasses respective assay instrument  108 —the carrier  101  is never received by intermediate conveyor assembly  133 —and is transported to a downstream portion  145  of host conveyor assembly  102  that transports the carrier  101  to a position (for example, downstream positions  141   b ,  141   c , and  141   a ) adjacent another assay instrument  108  operatively coupled to host conveyor assembly  102 . As for another example, host conveyor assembly  102  can be configured to transport a carrier  101  such that it bypasses both assay instruments  108   a  and  108   b —the carrier  101  is never received by intermediate assay conveyor assemblies  133   a  and  133   b —and is transported to a position (for example, position  141   c ) adjacent assay instrument  108   c . Or at position  141 , host conveyor assembly  102  is configured to transport carrier  101  to intermediate conveyor assembly  133  such that carrier  101  is transported to assay instrument  108 . 
     In some embodiments, host conveyor assembly  102  includes a diverter (for example, diverters  142   a ,  142   b , and  142   c , collectively referred to as diverters  142  or individually and generically referred to as diverter  142 ) adjacent position  141  and a respective intermediate conveyor assembly  133 . Diverter  142  is configured to selectively transport a carrier  101  (one at a time in some embodiments) from a portion (first portion  118  or second portion  120 ) of host conveyor assembly  102  to intermediate conveyor assembly  133  (for example, intermediate assay conveyor assemblies  133   a ,  133   b , or  133   c ) based on information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the carrier  101 , or both the carrier  101  and receptacle  103 . In some embodiments, diverter  142  is also configured to alternatively and selectively transfer a carrier  101  (one at a time in some embodiments) from position  141  on host conveyor assembly  102  to downstream portion  145  of host conveyor assembly  102  such that the carrier  101  bypasses the respective intermediate conveyor assembly  133  based on an information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the carrier  101 , or both the carrier  101  and receptacle  103 . 
     In some embodiments, diverter  142  is a rotatable disc that defines one or more recesses (for example, one recess as shown in  FIG. 2 ) configured to receive a carrier  101  at position  141  on an upstream portion of host conveyor assembly  102 . As diverter  142  rotates, the carrier  101  received within the recess defined by diverter  142  is transferred to either intermediate conveyor assembly  133  (for example, if diverter  142  rotates counter clockwise) or to downstream portion  145  of host conveyor assembly  102  (for example, if diverter  142  rotates clockwise) such that the carrier bypasses the respective intermediate conveyor assembly  133  based on information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both. For example, an upstream portion of host conveyor assembly  102  transports a carrier  101  such that it is received within a recess defined by diverter  142  at position  141 . Then based on information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both, diverter  142  rotates to a position that aligns the recess in which carrier  101  is received with either (1) downstream portion  145  of host conveyor assembly  102  (such that the carrier bypasses intermediate conveyor assembly  133  and assay instrument  108 ) or (2) a portion of intermediate conveyor assembly  133   a  such that the carrier can be subsequently transported to a processing position of assay instrument  108 . In some embodiments, diverter  142  is configured to rotate in one direction or in two directions about an axis of rotation. 
     In some embodiments, host conveyor assembly  102  includes a sensor (for example, sensors  144   a ,  144   b , and  144   c , collectively referred to as sensors  144  or individually and generically as sensor  144 ) configured to read the information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both. Sensor  144  can be positioned upstream from diverter  142 . Diverter  142  is operatively coupled to sensor  144  such that diverter  142  selectively transfers a carrier  101  from an upstream portion of host conveyor assembly  102  to either (1) an intermediate conveyor assembly  133  or (2) a downstream portion  145  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133  and assay instrument  108  based on the information (e.g., an identifier) on the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both read by sensor  144 . 
     In some embodiments, system  100  includes a control system (not shown in  FIG. 2 ) configured to transmit a control signal to diverter  142 . Diverter  142  is configured to transfer the carrier  101  from the upstream portion of host conveyor assembly  102  to either (1) an intermediate conveyor assembly  133  or (2) a downstream portion  145  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133  and assay instrument  108  based on the control signal received from the control system. And sensor  144  can be configured to transmit a signal to the control system based on the read information (e.g., an identifier) of the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both. The control system also can be configured to adjust the control signal transmitted to diverter  142  based on the sensor signal received from sensor  144  to control whether the carrier  101  is transported from an upstream portion of host conveyor assembly  102  to either (1) an intermediate conveyor assembly  133  or (2) a downstream portion  145  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133  and assay instrument  108 . 
     In some embodiments, at least one of the carrier  101  and the respective processing receptacle  103  includes an RFID tag that transmits an identifier, and sensor  144  is an RFID antenna configured to detect the identifier transmitted by the RFID tag on the at least one of carrier  101  and processing receptacle  103 . In other embodiments, at least one of the carrier  101  and the respective processing receptacle  103  includes a machine readable label, for example, a barcode, that includes an identifier, and sensor  144  is an image sensor, for example, a barcode reader, configured to detect the label on the at least one of carrier  101  and processing receptacle  103 . 
     In some embodiments, each of sensors  144   a ,  144   b , and  144   c  are the same type of sensor, and in other embodiments at least two of sensors  144   a ,  144   b , and  144   c  are different types of sensors. 
     In some embodiments, the path defined by host conveyor assembly  102  is substantially enclosed by a cover (not shown). The cover can help prevent contamination of samples within receptacles  103  coupled to carriers  101  being transported on host conveyor assembly  102 . 
     D. Exemplary Embodiments of Intermediate Conveyor Assemblies  133   
     Intermediate conveyor assembly  133  is configured to receive carriers  101  at position  141  on host conveyor assembly  102  and transport the carriers to a respective processing position (for example, processing positions  154   a ,  154   b ,  154   c , collectively referred to as processing positions  154  or individually referred to as processing position  154 ) of the assay instrument  108 . In some embodiments, position  154  is within a housing of the respective assay instrument  108 . In some embodiments, assay instrument  108  includes an automated pipettor configured to aspirate at least a portion of a sample from a processing receptacle  103  coupled to a carrier  101  positioned at processing position  154 . Automated pipettor  158  can also be configured to subsequently dispense the aspirated portion of the first sample from the processing receptacle  103  at processing position  154  into an assay receptacle  160 . Automated pipettor  158  and assay instrument  108  are described further below. 
     In some embodiments, intermediate conveyor assembly  133  is also configured to transport a carrier  101  from processing position  154  to another position outside the housing of assay instrument  108  (for example, positions  167   a ,  167   b , and  167   c , collectively referred to as positions  167  or individually referred to as position  167 ). In other embodiments, intermediate conveyor assembly  133  is configured to transport a carrier  101  from processing position  154  to another position inside the housing of assay instrument  108 . In some embodiments, intermediate conveyor assembly  133  is configured to transport a carrier  101 , after being positioned at processing position  154 , back to host conveyor assembly  102 . For example, intermediate conveyor assembly  133  can be configured to transport a carrier  101  at a position outside of the housing of assay instrument  108  (for example, position  167  in  FIG. 2 ), to host conveyor assembly  102 . 
     In some embodiments, each of intermediate conveyor assemblies  133   a - 133   c  is configured similarly (e.g., similar components, shape, size, and path along which carriers  101  are transported) as shown in  FIG. 2 . In other embodiments, at least two of intermediate conveyor assemblies  133   a - 133   c  are configured differently (e.g., different components, shape, size, or path along which carriers  101  are transported). 
     In some embodiments, intermediate conveyor assembly  133  includes a buffer conveyor subassembly  114  and a spur conveyor subassembly  116 .  FIGS. 3-10  illustrate embodiments of buffer conveyor subassembly  114  and a spur conveyor subassembly  116 , and are referenced collectively below in describing embodiments of buffer conveyor subassembly  114  and a spur conveyor subassembly  116 . 
     Buffer conveyor subassembly  114  can include an input portion  146  configured to receive a carrier  101  from host conveyor assembly  102  (for example, by diverter  142 ) and transport the carrier  101  to a position  147 . Buffer conveyor subassembly  114  can also include an output portion  162  configured to receive a carrier  101  at a position  163  from spur conveyor subassembly  116  and transport the carrier  101  to a position  167 . In some embodiments, position  147 , position  163 , and position  167  are each outside the housing of assay instrument  108 . In other embodiments, at least one of position  147 , position  163 , and position  167  are outside the housing of assay instrument  108 . In some embodiments (not shown), position  147  is collocated with position  163 —position  147  and position  163  are the same position. 
     Spur conveyor subassembly  116  is configured to transport a carrier  101  between a position  153  and the processing position  154  within the housing of assay instrument  108 . In some embodiments, position  153  is substantially outside the housing of assay instrument  108 , as best seen in  FIG. 2  and  FIG. 6 . In other embodiments (not shown), position  153  is inside the housing of assay instrument  108 . In some embodiments, as shown, spur conveyor subassembly  116  is configured to receive only one carrier  101  at a time. In other embodiments (not shown), spur conveyor subassembly  116  is configured to receive more than one carrier  101  at a time. 
     Spur conveyor subassembly  116  can include a diverter  150  configured to transport a carrier  101  from position  147  on buffer conveyor subassembly  114  to position  153  on spur conveyor subassembly  116 . And in some embodiments, diverter  150  is configured to transport a carrier  101  from position  147  to position  153  while simultaneously transporting another carrier  101  from position  153  to position  163  on buffer conveyor subassembly  114 . Simultaneously transporting one carrier  101  from position  147  to position  153  while transporting another carrier  101  from position  153  to position  163  can increase throughput of spur conveyor subassembly  116  and, in turn, assay instrument  108 . 
     Diverter  150  can define a plurality of recesses for receiving and transporting carriers  101 . For example, as best seen in  FIGS. 5 and 6 , diverter  150  can define three recesses  155 , each configured to closely receive a carrier  101 . In other embodiments, diverter  150  defines more than or less than three recesses  155 . For example, diverter  150  can define one recess  155  or five recesses  155 . In some embodiments, as illustrated, diverter  150  has a circular periphery with three concave, circular recesses  155 . Recesses  155  can be evenly spaced around the periphery of diverter  150 , as best seen in  FIGS. 4 and 5 . For example, if diverter  150  has three recesses  155 , the recesses can be positioned about 120 degrees apart (about a center point of diverter  150 ). 
     In some embodiments, recesses  155  are positioned on diverter  150  such that when one recess  155  is aligned with position  147  on buffer conveyor subassembly  114 , one recess  155  is aligned with position  153  spur conveyor subassembly  116 , and one recess  155  is aligned with position  163  of buffer conveyor subassembly  114 . Such a configuration allows diverter  150  to receive one carrier  101  at position  147  simultaneously with either (1) receiving or releasing another carrier  101  at position  153  or (2) releasing another carrier  101  at position  163 . Accordingly, diverter  150  can transport a carrier  101  from position  147  to position  153  while simultaneously transporting another carrier  101  from position  153  to position  163 . 
     As best seen in  FIGS. 4 and 5 , diverter  150  is configured to rotate about an axis of rotation. In some embodiments, diverter  150  is configured to rotate in one direction or in two directions. 
     Spur conveyor subassembly  116  can include a drive assembly  202  that is operatively coupled to diverter  150  to selectively rotate diverter  150  about the axis of rotation. Drive assembly  202  can include a motor that is operatively coupled to an axle coupled to diverter  150  via, for example, one or more of gears, pulleys, and belts that drive the axle coupled to diverter  150 . For example, referencing  FIG. 22 , drive assembly  202  can include a motor  325  that rotates a drive shaft  326  operatively coupled to motor  325 . As shown in  FIG. 22 , drive shaft  326  is substantially vertical in some embodiments. Drive shaft  326  can include a pulley  328  operatively coupled to a drive belt  330 . As shown in  FIG. 22 , drive belt  330  is substantially horizontal in some embodiments. Drive belt  330  is operative coupled to a pulley  332  fixedly connected to a rotating shaft  334 . Rotating shaft  334  is substantially vertical, as shown in  FIG. 22  in some embodiments. And diverter  150  is fixedly coupled to shaft  334 . The motor of drive assembly  202  is selectively activated to rotate shaft  326  and pulley  328 , which in turn rotates belt  330 . As belt  330  rotates, pulley  332  and shaft  334  rotate, which in turn rotates diverter  150 . 
     In some embodiments, as best seen in  FIG. 7 , drive assembly  202  is positioned between a housing panel  168  of instrument  108  and a track of buffer conveyor subassembly  114 . In some embodiments, the motor of drive assembly  202  is coupled to a mounting bracket  204  of spur conveyor subassembly  116 . Mounting bracket  204  positions the motor of drive assembly  202  below diverter  150  in some embodiments as shown in  FIGS. 5 and 7 . As best seen in  FIG. 22 , mounting bracket  204  can enclose substantially the entire drive assembly  202  in some embodiments. 
     In some embodiments as best seen in  FIGS. 3, 4, 6, 7, 9, and 10 , buffer conveyor subassembly  114  includes a single movable track, and diverter  150  of spur conveyor subassembly  116  dissects the single movable track of buffer conveyor subassembly  114  into input portion  146  and output portion  162 . In such embodiments, a portion of diverter  150  overlaps in a vertical direction at least a portion of the single movable track of buffer conveyor subassembly  114  input portion  146 . In such embodiments, the single movable track of buffer conveyor subassembly  114  transports a carrier  101  received from host conveyor assembly  102  in the direction of the annotated arrows in  FIGS. 2 and 10  along input portion  146 , and diverter  150  stops the carrier  101  at position  147  if position  147  is unoccupied by another carrier  101 . If position  147  is already occupied by a carrier  101 , the subsequent carrier  101  being transported by input portion  146  is stopped by the carrier  101  at position  147 . 
     In some embodiments, input portion  146  of buffer conveyor subassembly  114  has a length sufficient to queue a plurality of carriers  101  between diverter  150  and diverter  142   a  on host conveyor assembly  102 . For example, in some embodiments, input portion  146  has a length sufficient to queue at least five carriers  101 , for example, at least fifteen carriers  101 . 
     In some embodiments in which buffer conveyor subassembly  114  includes a single movable track, buffer conveyor subassembly  114  includes a pair of rotating axles  174  and  176  around which the movable track moves. In such embodiments, buffer conveyor subassembly  114  can include a drive assembly  172  that powers the movable track. For example, drive assembly  172  can be operatively coupled to one of the axles  174  and  176 , for example, axle  174  as shown in  FIG. 4 . Drive assembly  172  can include a motor that is operatively coupled to axle  174  via, for example, one or more of gears, pulleys, and belts that drive axle  174  and, in turn, the movable track. In some embodiments, drive assembly  172  is positioned between a housing panel  168  of instrument  108  and the track of buffer conveyor subassembly  114  as best seen in  FIG. 4 . 
     In some embodiments, buffer conveyor subassembly  114  is mounted to an outer surface of housing panel  168  of assay instrument  108  as best seen in  FIG. 3 . In some embodiments, housing panel  168  is a rear housing panel of assay instrument  108  on a side opposite of a manual input bay of assay instrument  108 . In such embodiments, the path along which carriers  101  are transported along buffer conveyor subassembly  114 , which includes position  147 ,  163 , and  167 , is outside the housing of assay instrument  108 . In some embodiments, as best seen in  FIGS. 3 and 4 , the path defined by buffer conveyor subassembly  114  is substantially parallel to housing panel  168  to which the buffer conveyor subassembly  114  is mounted. Buffer conveyor subassembly  114  can include a pair of mounting brackets  178  configured to secure buffer conveyor subassembly  114  to an outer surface of housing panel  168 . In some embodiments, the path defined by buffer conveyor subassembly  114  is substantially parallel to the path defined by an adjacent portion of host conveyor assembly  102 . 
     Buffer conveyor subassembly  114  can also include a carrier alignment bracket  180  in some embodiments, as best seen in  FIG. 4 . Alignment bracket  180  is shaped to push a carrier  101  to position  147  as the carrier  101  is transported by buffer conveyor subassembly  114  towards diverter  150 . For example, the alignment bracket  180  can have a surface that is at an obtuse angle relative to the path defined by buffer conveyor subassembly  114  along which carriers  101  are transported. As the carrier  101  contacts this surface, the carrier  101  is pushed toward position  147  on buffer conveyor subassembly  114 . 
     In some embodiments, buffer conveyor subassembly  114  also includes a sensor  148  configured to detect the presence of a carrier  101  at position  147  and/or read information (for example, an identifier) from a carrier  101 , a receptacle  103  coupled to the carrier  101 , or both the carrier and the receptacle  103 . In some embodiments, diverter  150  is operably coupled to sensor  148  such that when a carrier  101  is detected to be at position  147  (and within a recess  155  defined by diverter  150 ), rotation of diverter  150  is actuated, and the carrier  101  is transported to position  153  on a portion  184  of spur conveyor subassembly  116 . In some embodiments, sensor  148  is positioned on alignment bracket  180  or any other position near diverter  150 . Sensor  148  can be an optical sensor or an RFID antenna. 
     Turning back to spur conveyor subassembly  116 , subassembly  116  receives a carrier  101  from diverter  150  at position  153 . Spur conveyor subassembly  116  is configured to transport the carrier  101  between position  153  and the processing position  154  within the housing of assay instrument  108 . In some embodiments, housing panel  168  of assay instrument  108  defines an opening  170 , and spur conveyor subassembly  116  extends from buffer conveyor subassembly  114  and through opening  170  into the interior of assay instrument  108 . In some embodiments, opening  170  is sized such that a carrier  101  and processing receptacle  103  coupled thereto can pass through opening  170 . 
     Spur conveyor subassembly  116  can be coupled to buffer conveyor subassembly  114 . In some embodiments, as best shown in  FIGS. 2-4 and 6 , spur conveyor subassembly  116  is coupled to buffer conveyor subassembly  114  at a position that is aligned with diverter  150 . In some embodiments as best seen in  FIGS. 4 and 6 , spur conveyor subassembly  116  is substantially perpendicular to buffer conveyor subassembly  114 . In other embodiments (not shown), spur conveyor subassembly  116  is at a non-perpendicular angle relative buffer conveyor subassembly  114 . In some embodiments, spur conveyor subassembly  116  bisects buffer conveyor subassembly  114 . 
     In some embodiments as best seen in  FIG. 5 , spur conveyor subassembly  116  includes a movable gripper  188  that is movably coupled, for example, translatably coupled, to a base  186 . For example, base  186  can define a groove (not shown), and gripper  188  can define a flange (not shown) translatably received within the groove of base  186 , which allows gripper  188  to move relative to base  186  in the direction of the groove. Gripper  188  can move along a direction  190 . Gripper  188  is configured to selectively grasp a carrier  101  at position  153  and transport the carrier  101  (along with the coupled processing receptacle  103 ) to the processing position  154  within a housing of assay instrument  108 . 
     Referencing  FIGS. 5 and 22-26 , gripper  188  of spur conveyor subassembly  116  can include at least two movable prongs  189  configured to secure the carrier  101  to gripper  188 , for example, by applying an effective amount of pressure to a carrier  101 . As shown in  FIGS. 5 and 22-26 , gripper  188  has two movable prongs  189 . In some embodiments, movable prongs  189  are pivotally coupled to a base  197  of gripper  188 . For example, each movable prong  189  can be coupled to base  197  using a pivot pin  199  extending (e.g., substantially vertically) from base  197  about which each prong  189  pivots. Base  197  can be configured to engage a bottom surface of carrier  101 . For example, when diverter  150  transports a carrier  101  from position  147  on buffer conveyor subassembly  114  to position  153  on spur conveyor subassembly  116 , diverter  150  places the carrier  101  on top of base  197  of gripper  188 . After the carrier  101  is transferred to base  197  of gripper  188 , movable prongs  189  grasp carrier  101  by pivoting about pivot pin  199  toward each other and applying an effective amount of pressure to carrier  101  to secure the carrier  101  to gripper  188 . 
     Gripper  188  can also include a wall  205  extending (e.g., substantially vertically) from base  197  of gripper  188 . Wall  205  is configured to stop movement of a carrier  101  in a direction toward processing position  154  when diverter  150  transports a carrier  101  from position  147  on buffer conveyor subassembly  114  to position  153  on spur conveyor subassembly  116 . In some embodiments, wall  205  is spaced apart from pivot pin  199  in a direction toward buffer subassembly  114 . 
     In some embodiments, each prong  189  includes a first prong portion  191  that extends substantially perpendicularly (for example, vertically) away from base  186 . First prong portion  191  can have a shape that closely corresponds to the perimeter of carrier  101 . For example, if carrier  101  is a circular puck, first prong portion  191  can have a corresponding arcuate shape that closely corresponds the circularly periphery of carrier  101 . In some embodiments, each prong  189  of gripper  188  also includes a second prong portion  193  that extends substantially perpendicularly (for example, horizontally) from first portion  191  towards a center of gripper  188 . When gripper  188  is grasping a carrier  101 , second prong portion  193  overlaps (in a vertical direction) at least a portion of carrier  101  as best shown in  FIG. 5 . 
     In some embodiments (as best seen in  FIG. 26 ), first prong portion  191  of prong  189  defines a protrusion  206  on a surface facing a carrier  101  on base  197  of gripper  188 . Protrusion  206  is configured to be received in a groove  302  defined by carrier  101 , which is explained further below in reference to  FIGS. 17 and 18 , when gripper  188  is in a closed configuration. When gripper  188  is in the closed configuration, protrusion  206  overlaps (in a vertical direction) at least a portion of the surface defining groove  302  of carrier  101 . If a force is applied to carrier  101  in a direction away from base  186  of spur conveyor subassembly  116 , protrusion  206  substantially prevents movement of carrier  101  in a direction of the applied forces, which secures carrier  101  to gripper  188  and spur conveyor subassembly  116 . For example (referencing  FIG. 8 ), protrusion  206  can hold carrier  101  down as a distal end of pipettor  158  of assay instrument  108  is removed from a processing receptacle  103  coupled to the carrier  101  at processing position  154 . Removing the distal end of pipettor  158  from processing receptacle  103  can generate a force in the direction of movement of pipettor  158 , and protrusion  206  of prongs  189  can hold the carrier  101  down. For example, in some embodiments, receptacle  103  includes a cap  159 . Cap  159  defines a hollow cavity that is sealed on top with a metallic foil  161 . The hollow cavity of cap  159  can be filled with a porous filter  165 , and the bottom of the hollow cavity is sealed with another metallic foil  169 . As the distal end of pipettor  158  is removed from processing receptacle  103 , the distal end passes through the bottom foil  169 , the filter  165 , and the top metallic foil  161 , generating a force in the direction of movement of pipettor  158 . Protrusions  206  of prongs  189  hold carrier  101  in place by resisting this generated force. 
     In some embodiments (not shown), first prong portion  191  and second prong portion  193  are sized such that second portion  193  contacts the overlapped surface (for example, a top surface) of carrier  101  coupled to gripper  188  when gripper  188  is in the closed configuration. This way, if a force is applied to carrier  101  in a direction away from base  186  of spur conveyor subassembly  116 , second prong portion  193  substantially prevents movement of carrier  101  in a direction of the applied forces, which secures carrier  101  to gripper  188  and spur conveyor subassembly  116 . For example (referencing  FIG. 8 ), second prong portion  193  can hold carrier  101  down as a distal end of pipettor  158  of assay instrument  108  is removed from a processing receptacle  103  coupled to a carrier  101  at processing position  154 . Removing the distal end of pipettor  158  from processing receptacle  103  can apply a force in the direction of movement of pipettor  158 , and second prong portions  193  of prongs  189  can hold the carrier  101  down. 
     In some embodiments, second prong portions  193  of gripper prongs  189  are sized such than when prongs  189  are at a fully closed and grasping carrier  101  (i.e., at the closed configuration of gripper  188 ), there is a gap between the second prong portions  193  of prongs  189 . This gap is sized to allow processing receptacle  103  to extend from carrier  101  in a direction away from base  186 . The second prong portions  193  are sized such that the distal ends of each second prong portion  193  contact a processing receptacle  103  passing through the gap defined there between, thereby applying a force to receptacle  103  as best seen in  FIGS. 25 and 26 . This contact generates an axial retaining force (e.g., via friction) on receptacle  103  that secures receptacle  103  to carrier  101  when a force is applied to receptacle  103  in a direction away from carrier  101  and base  186  of spur conveyor subassembly  116  (for example, a force applied to receptacle  103  when the distal end of pipettor  158  is removed from receptacle  103 ). In some embodiments, each second prong portion  193  includes an elastomeric (for example, rubber) portion  195  that contacts receptacle  103 . Elastomeric portion  195  can be configured to compress (which in turn enlarges the gap between second prong portions  193  through which a receptacle  103  passes) when contacting the receptacle  103 . This compression allows gripper  188  to accommodate receptacles  103  having varying diameters, for example, diameters varying from about 8 mm to about 20 mm, including diameters of 12 mm and 16 mm. Elastomeric portion  195  can also increase the coefficient of friction at the interface between second prong portion  193  and receptacle  103 , which increases the axial retaining force gripper  188  generates while grasping receptacle  103  with prongs  189 . In some embodiments, the contact of second prong portions  193  against receptacle  103  can also help align receptacle  103  in a desired orientation (for example, in the vertical orientation) within spur conveyor subassembly  116 . 
     Gripper  188  is configured to move between (1) an open configuration at which a carrier  101  is capable of moving relative to gripper  188  and (2) a closed configuration at which carrier  101  is secured to gripper  188 . For example,  FIG. 24  illustrates gripper  188  at the open configuration. At the open configuration, prongs  189  of gripper  188  are separated from each other such that prongs  189  do not contact carrier  101  or receptacle  103 . Accordingly, protrusion  206  of each prong  189  is not received within groove  302  of carrier  101 , and elastomeric portion  195  of each prong  189  does not contact receptacle  103 . This open configuration of gripper  188  allows diverter  150  to easily (1) transfer a carrier  101  from position  147  on buffer conveyor subassembly  114  to position  153  on spur conveyor subassembly  116  such that carrier  101  is placed on top of base  197  of gripper  188 , and/or (2) transfer another carrier  101  from position  153  on spur conveyor subassembly  116  to position  163  on buffer conveyor subassembly  114 . In some embodiments, prongs  189  are biased to the closed configuration, for example, by using an extension spring  211 . In other embodiments, prongs  189  are unbiased or biased to the open configuration using, for example, a compression spring. 
       FIGS. 25 and 26  illustrate gripper  188  at the closed configuration according to an embodiment. After carrier  101  is transferred onto base  197  of gripper  188  by diverter  150 , gripper  188  moves to the closed configuration by pivoting prongs  189  about pivot pin  199  towards each other until prongs  189  contact the carrier  101  and apply an effective amount of pressure to the carrier  101  to secure the carrier  101  to gripper  188 . At the closed configuration, protrusion  206  of each prong  189  is received within groove  302  of carrier  101 , and elastomeric portion  195  of each prong  189  contacts receptacle  103 . At the closed configuration, if a force is applied to carrier  101  in a direction away from base  186  of spur conveyor subassembly  116 , protrusion  206  substantially prevents movement of carrier  101  in a direction of the applied forces, thereby securing carrier  101  to gripper  188  and spur conveyor subassembly  116 . And at this closed configuration, the generated axial retaining force (e.g., via friction) on receptacle  103  by elastomeric portions  195  can secure receptacle  103  to carrier  101  when a force is applied to receptacle  103  in a direction away from carrier  101  and base  186  of spur conveyor subassembly  116 . 
     In some embodiments, spur conveyor subassembly  116  is configured to move prongs  189  of gripper  188  to the open configuration when gripper  188  is at position  153 . At position  153 , gripper  188  receives a carrier  101  transferred by diverter  150  from buffer subassembly  114  and/or delivers a carrier  101  to be transferred by diverter  150  to buffer subassembly  114 . And spur conveyor subassembly  116  is configured to move prongs  189  of gripper  188  to the closed configuration after carrier  101  is placed onto base  197  of gripper  188 . In some embodiments, prongs  189  move to the closed configuration while gripper  188  is at position  153 , and in other embodiments, prongs  189  move to the closed configuration after gripper  188  moves from position  153  and towards processing position  154 . Spur conveyor subassembly  116  is also configured to maintain prongs  189  of gripper  188  at the closed configuration when gripper  188  is at the processing position  154 , thereby ensuring carrier  101  and processing receptacle  103  are held down as a distal end of pipettor  158  of assay instrument  108  is removed from processing receptacle  103 . 
     In some embodiments, movement of prongs  189  between the open and closed configurations is actuated by a cam interface. For example, base  186  of spur conveyor subassembly  116  can define a pair of elongated and symmetric grooves  207  that extend from processing position  154  to position  153 . Proximate processing position  154  grooves  207  are substantially parallel, and proximate position  153  grooves  207  extend outward away from each other in a substantially V- or U-shape fashion. Each prong  189  includes a pin  209  (best shown in  FIGS. 23 and 26 ) configured to be received within a respective groove  207 . As gripper  188  moves along spur conveyor subassembly  116 , pins  209  of prongs  189  interface with the surfaces defining grooves  207 , which moves prongs  189  between the open and closed configurations. For example, as gripper  188  moves towards position  153 , pins  209  move outwards as they each travel in a respective outwardly extending portion of a respective groove  207 , which in turn moves prongs  189  to the open configuration via a cam interface between pins  209  and the surface that defines grooves  207 . And as gripper  188  moves back towards processing position  154 , pins  209  move inward as they travel back towards the parallel portion of grooves  207 , which in turn moves prongs  189  to the closed configuration via a cam interface between pins  209  and the surface that defines grooves  207 . 
     In other embodiments, movement of prongs  189  between the open and closed configurations is selectively controlled by electro-mechanical configurations. For example, gripper  188  can include another drive assembly (e.g., a motor with belts, links, or gears) operatively coupled to prongs  189 . The drive assembly can move prongs  189  between the open and closed configurations. 
     Spur conveyor subassembly  116  can also include a drive assembly  192  mounted to base  186 . Drive assembly  192  is configured to selectively move gripper  188  along direction  190 . In some embodiments, drive assembly  192  includes a motor operatively coupled to gripper  188  via one or more gears, pulleys, links, or belts. In some embodiments, drive assembly  192  is positioned on a side of processing position  154  away from position  153  of spur conveyor subassembly  116 . For example, referencing  FIG. 22 , drive assembly  192  can be operatively coupled to a drive belt  320  that is operatively coupled to gripper  188 , for example, to base  197  of gripper  188 . Drive belt  320  can be rotationally mounted to spur conveyor subassembly  116  by a pair of rotating axles  322  and  324 . Drive assembly  192  is operatively coupled to axle  322  by one or more of gears, pulleys, and belts (not shown in  FIG. 22 ) to power axle  322  and, thereby, move belt  320 . The position of gripper  188  is fixed relative to drive belt  320 . Referencing  FIG. 22 , as drive belt  320  rotates in a counter-clockwise direction, gripper  188  moves towards diverter  150 , and as drive belt  320  rotates in a clockwise direction, gripper  188  moves towards processing position  154 . 
     In other embodiments, instead of or in addition to gripper  188 , spur conveyor subassembly  116  includes a single movable track that transports carrier  101  between position  153  and processing position  154 . Drive assembly  192  is configured to selectively move the track and, in turn, transport a carrier  101  in both directions  190 . In such embodiments, a carrier  101  can sit on top of the movable track as the track moves with the carrier  101 . 
     For example, in some embodiments, a movable track moves carrier  101  from position  153  to processing position  154 , and at processing position  154 , a stationary gripper  188  grasps carrier  101  securing carrier  101  at processing position  154 . After gripper  188  grasps carrier  101 , automated pipettor  158  can aspirate a portion of a sample in a receptacle coupled to the carrier  101  being grasped by gripper  188 . After a sample is aspirated, gripper  188  can release the carrier  101 , and the movable track can transport the carrier back to position  153 . 
     In some embodiments, spur conveyor subassembly  116  includes both gripper  188  and diverter  150 . In other embodiments, spur conveyor subassembly  116  omits one of either gripper  188  or diverter  150 . For example, spur conveyor subassembly  116  can include gripper  188 , but not diverter  150 , or spur conveyor subassembly  116  can include diverter  150 , but not gripper  188 . 
     Spur conveyor subassembly  116  can also include a cover  182  in some embodiments. Cover  182  overlaps at least a portion of the path defined by spur conveyor subassembly  116  to help prevent cross-contamination from substances dropping from pipettor  158  as it moves within the housing of assay instrument  108  or from other processes occurring within the housing of assay instrument  108 . In some embodiments, cover  182  overlaps substantially the entire portion  183  (shown in  FIG. 4 ) of the path between position  153  and processing position  154  that is within the housing of assay instrument  108 . For example, one end of cover  182  is adjacent an inner surface of housing panel  168  of assay instrument  108 , which defines opening  170 , and the other end of cover  182  is adjacent and overlaps processing position  154 . Accordingly, when position  153  is outside the housing of assay instrument  108  and processing position  154  is within the housing of assay instrument  108 , a portion  184  of the path defined by spur conveyor subassembly  116  is outside the housing and uncovered, but the portion  183  of the path defined by spur conveyor subassembly  116  that is inside the housing and is covered and substantially enclosed by cover  182 , thereby reducing the risk of cross-contamination. Cover  182  is sized and shaped to allow processing receptacle  103  coupled to a carrier  101  to pass from position  153  to processing position  154 . In some embodiments as shown in  FIG. 5 , cover  182  has a substantially inverted U-shape, or any other suitable shape. 
     In some embodiments, a portion of cover  182  overlapping processing position  154  defines an opening  194 . Opening  194  can be circular in some embodiments as shown in  FIGS. 5, 6, and 8 . Opening  194  is configured to allow a distal end of pipettor  158 , for example, which includes a disposable tip or probe, to pass and then be inserted into processing receptacle  103  coupled to carrier  101 , which is positioned at processing position  154  and secured at that position  154  by gripper  188 . In some embodiments, cover  182  also includes an alignment plate  196 . As shown in  FIG. 5 , alignment plate  196  is a separate component from the remainder of cover  182 . But in other embodiments, alignment plate  196  can be formed integrally with the remainder of cover  182 . Alignment plate  196  defines a tapered surface that surrounds opening  194  defined by cover  182 . The tapered surfaces can automatically align the distal end of pipettor  158  as the distal end of pipettor  158  is moved toward processing receptacle  103  if pipettor  158  is slightly misaligned relative to receptacle  103 . 
     Cover  182  can be coupled to base  186 . In some embodiments, cover  182  is removably coupled to base  186 . In such removable embodiments, cover  182  can be removed for cleaning. In other embodiments, cover  182  is permanently coupled to base  186 . In some embodiments, cover  182  is composed of a material compatible with being decontaminated in a bleach solution. 
     In other embodiments (not shown), instead of cover  182  being part of spur conveyor subassembly  116 , cover  182  is part of assay instrument  108 . 
     Spur conveyor subassembly  116  can also include a receptacle alignment block  198  in some embodiments. Alignment block  198  is configured to automatically align a processing receptacle  103  coupled to a carrier  101  at the processing position  154  at an orientation aligned with the direction of travel of pipettor  158  (for example, receptacle alignment block  198  can orient receptacle  103  in a vertical orientation). Alignment block  198  defines a recess configured to receive a portion of receptacle  103  coupled to a carrier  101  at the processing receptacle  103 . As the portion of receptacle  103  is received within this recess defined by alignment block  198 , processing receptacle  103  coupled to the carrier  101  is automatically aligned with the direction of travel of pipettor  158  and with opening  194  defined by cover  182 . In some embodiments, alignment block  198  is positioned on a side of processing position  154  away from position  153 . 
     As shown in  FIG. 8 , pipettor  158  of assay instrument  108  is configured to move along direction  210 . As pipettor  158  moves in direction  210  toward base  186 , a distal tip of pipettor  158  is inserted through opening  194  defined by cover  182  until it is inserted within processing receptacle  103 , which is coupled to a carrier  101  positioned at processing position  154 . 
     In some embodiments, spur conveyor subassembly  116  includes a sensor  156  configured to detect information (e.g., an identifier) of the carrier  101 , the processing receptacle  103  coupled to the carrier  101 , or both, when the carrier  101  is positioned at processing position  154  of assay instrument  108 . For example, in some embodiments, sensor  156  is positioned near a terminal end of the path defined by spur conveyor subassembly  116  along which a carrier  101  is transported. In some embodiments, sensor  156  is covered by cover  182 . In some embodiments, sensor  156  is adjacent base  186  of spur conveyor subassembly  116  and is below gripper  188 . In some embodiments, assay instrument  108  is configured to start aspirating at least a portion of a sample from the processing receptacle  103  coupled to a carrier  101  at the processing position  154  of assay instrument  108  based on the detected identifier of the carrier  101 , the processing receptacle  103  coupled to the respective carrier  101 , or both, by sensor  156 . In some embodiments in which at least one of the carrier  101  and the respective processing receptacle  103  includes an RFID tag that transmits an identifier or other information, sensor  156  is an RFID antenna configured to detect the identifier or other information transmitted by the RFID tag on the at least one of carrier  101  and processing receptacle  103 . In other embodiments in which at least one of the carrier  101  and the respective processing receptacle  103  includes a machine readable label, for example, a barcode, that includes the identifier or other information, sensor  156  is an image sensor, for example, a barcode reader, configured to detect the label on the at least one of carrier  101  and processing receptacle  103 . In some embodiments, sensor  156  is also configured to detect the presence of a carrier  101  at position  154 . 
     Intermediate conveyor assembly  133  includes a controller  200 . In some embodiments, controller  200  is positioned on spur conveyor subassembly  116 . For example, controller  200  can be mounted to cover  182 . In some embodiments, controller  200  includes one or more processors, one or more of drivers for the drive assemblies, and one or more communication interfaces as described further below. In some embodiments, controller  200  is operatively coupled to one or more of drive assembly  172  of buffer conveyor subassembly  114 , drive assembly  202  of diverter  150 , and drive assembly  192  of gripper  188  to control the operations of these components. 
       FIGS. 11-13  schematically illustrate various exemplary system architectures of controller  200  relative to host conveyor assembly  102  and assay instrument  108 . 
     As shown in  FIG. 11 , controller  200  is operatively and directly coupled to buffer conveyor subassembly  114  via one or more communication links  212  and spur conveyor subassembly  116  via one or more communication links  214  in some embodiments. In such embodiments, controller  200  can directly control the track of buffer conveyor subassembly  114  and the gripper  188  of spur conveyor subassembly  116  via respective communication links  212  and  214 . For example, controller  200  can send a control signal via communication link  212  to drive assembly  172  of buffer conveyor subassembly  114 , and controller  200  can send a control signal via communication link  214  to drive assembly  192  of spur conveyor subassembly  116 . Controller  200  can also directly monitor the sensors of buffer conveyor subassembly  114  and the sensors of spur conveyor subassembly  116 . For example, controller  200  can receive a signal via communication link  212  from sensor  148  on buffer conveyor subassembly  114  that is indicative of whether a carrier  101  is present at position  147 , and controller  200  can receive a signal via communication link  214  from sensor  156  on spur conveyor subassembly  116  indicative of information, for example, an identifier, detected from carrier  101 , receptacle  103 , or both, when the carrier  101  is at processing position  154 . Controller  200  can also directly control diverter  150  on spur conveyor subassembly  116  using a control signal transmitted via communication link  214 . In some embodiments, controller  200  controls diverter  150  by adjusting the control signal transmitted to diverter  150  based on the signal received from sensor  148 . In some embodiments, controller  200  is in communication with the controllers of assay instruments  108  via one or more communication links  218 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces. Controller  200  is also in communication with the controller of host conveyor assembly  102  via one or more communication links  216 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces. 
     As shown in  FIG. 12 , controller  200  is operatively and directly coupled to only spur conveyor subassembly  116  via one or more communication links  214  according to another embodiment. Controller  200  can directly control the track of spur conveyor subassembly  116  via communication link  214 . For example, controller  200  can send a control signal via communication link  214  to drive assembly  192  of spur conveyor subassembly  116 . Controller  200  can also directly monitor the sensors of spur conveyor subassembly  116 . For example, controller  200  can receive a signal via communication link  214  from sensor  156  on spur conveyor subassembly  116  indicative of information, for example, an identifier, detected from carrier  101 , receptacle  103 , or both, when the carrier  101  is at processing position  154 . Controller  200  can also directly control diverter  150  on spur conveyor subassembly  116  using a control signal transmitted via communication link  214 . In some embodiments, the controller of host conveyor assembly  102  can directly control buffer conveyor subassembly  114  via one or more communication links  220 . For example, the controller of host conveyor assembly  102  can directly control the track of buffer conveyor subassembly  114  via communication link  220 . For example, the controller of host conveyor assembly  102  can send a control signal via communication link  220  to drive assembly  172  of buffer conveyor subassembly  114 . The controller of host conveyor assembly  102  can also directly monitor the sensors of buffer conveyor subassembly  114 . For example, the controller of host conveyor assembly  102  can receive a signal via communication link  220  from sensor  148  on buffer conveyor subassembly  114  that is indicative of whether a carrier  101  is present at position  147 . In some embodiments, the controller of host conveyor assembly  102  controls diverter  150  by adjusting the control signal transmitted to diverter  150  based on the signal received from sensor  148 . Controller  200  is in communication with the controllers of assay instruments  108  via one or more communication links  218 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces. Controller  200  is also in communication with the controller of host conveyor assembly  102  via one or more communication links  216 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces. 
     As shown in  FIG. 13 , the controller of host conveyor assembly  102  is operatively and directly coupled to buffer conveyor subassembly  114  via one or more communication links  222  and to spur conveyor subassembly  116  via one or more communication links  220  according to another embodiment. In such embodiments, the controller of host conveyor assembly  102  can directly control the track of buffer conveyor subassembly  114  and gripper  188  of spur conveyor subassembly  116  via respective communication links  220  and  222 . For example, the controller of host conveyor assembly  102  can send a control signal via communication link  220  to drive assembly  172  of buffer conveyor subassembly  114 , and the controller of host conveyor assembly  102  can send a control signal via communication link  222  to drive assembly  192  of spur conveyor subassembly  116 . The controller of host conveyor assembly  102  can also directly monitor the sensors of buffer conveyor subassembly  114  and spur conveyor subassembly  116 . For example, the controller of host conveyor assembly  102  can receive a signal via communication link  220  from sensor  148  on buffer conveyor subassembly  114  that is indicative of whether a carrier  101  is present at position  147 , and the controller of host conveyor assembly  102  can receive a signal via communication link  222  from sensor  156  on spur conveyor subassembly  116  indicative of information, for example, an identifier, from carrier  101 , receptacle  103 , or both, when the carrier  101  is at processing position  154 . The controller of host conveyor assembly  102  can also directly control diverter  150  on buffer conveyor subassembly  114  using a control signal transmitted via communication link  220 . In some embodiments, the controller of host conveyor assembly  102  controls diverter  150  by adjusting the control signal transmitted to diverter  150  based on the signal received from sensor  148 . In such embodiments, controller  200  is in communication with the controllers of assay instruments  108  via one or more communication links  218 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces, and controller  200  is also in communication with the controller of host conveyor assembly  102  via one or more communication links  216 , for example, CAN, RS485, RS422, Ethernet, USB, or wireless communication interfaces. 
       FIG. 14  schematically illustrates a configuration of system  100  that also includes a lab information system  223 . As shown in  FIG. 14 , system  100  includes a lab information system  223 , processing instrument  104 , and a plurality of assay instruments  108   a - 108   c . The controller of processing instrument  104  is in communication with lab information system  223  via one or more communication links  228 . And the controller of processing instrument  104  is in communication with the controller of host conveyor assembly  102  via one or more communication links  230 . As explained above, the controller of host conveyor assembly  102  can be in communication with controllers  200   a - c  of respective intermediate conveyor assemblies  133   a - 133   b  via respective one or more communication links  216   a - c . Controllers  200   a - c  are in communication with respective communication interfaces  232   a - c , for example, COP modules, of controllers  226   a - c  of respective assay instruments  108   a - c  via respective one or more communication links  234   a - c . Controllers  226   a - 226   c  of assay instruments  108   a - c  are in communication directly or indirectly with lab information system  223 . For example, as shown in  FIG. 14 , controllers  226   a - c  of assay instruments  108   a - c  are directly in communication with an intermediate communication module  236  via respective communication links  238   a - c . In some embodiments, intermediate communication module  236  acts as a firewall between lab information system  223  and assay instruments  108 . Intermediate communication module  236  is in communication with lab information system  223  via one or more communication links  240 . In some embodiments, intermediate communication module  236  is omitted such that controllers  226   a - 226   c  communicate directly with lab information system  223  via communication links  238   a - c . In some embodiments, communication links  228 ,  230 ,  216   a - 216   c ,  218   a - 218   c ,  234   a - 234   c ,  238   a - 238   c , and  240  can be any one of CAN, RS485, RS422, Ethernet, USB, wireless communication interfaces, or a combination thereof. 
       FIG. 15  schematically illustrates a controller  200  operatively and directly coupled to buffer conveyor subassembly  114  and spur conveyor subassembly  116  according to an embodiment. As shown in  FIG. 15 , controller  200  includes a processor  242 , for example, a microcontroller such as a PIC microcontroller. Controller  200  includes one or more communication interfaces, for example, a CAN interface  244 A, an Ethernet interface  244 B, an isolated CAN interface  244 C, an isolated RS485 and/or RS422 interface  244 D, a USB interface  244 E for programming or debugging, or any combination thereof. Controller  200  can also include one or more power supplies  246 , for example, a 3.3 VDC or 12.0 VDC power supply. 
     Controller  200  can also include one or more drivers  248  for controlling one or more drive assemblies of spur conveyor subassembly  116 . For example, controller  200  can include one stepper motor driver  248  for controlling drive assembly  192  that moves gripper  188  of spur conveyor subassembly  116 , and another stepper motor driver for controlling drive assembly  202  that moves diverter  150 . 
     Controller  200  can further include one or more RFID interfaces  250  for communicating with interfaces of RFID sensors on buffer conveyor subassembly  114  and spur conveyor subassembly  116 . For example, controller  200  can include one RFID interface  250  for communicating with an RFID interface  264  of RFID sensor  156  on spur conveyor subassembly  116 , and include another RFID interface  250  for communicating with an RFID interface  264  of an optional RFID sensor  262  on buffer conveyor subassembly  114 . 
     Additionally, controller  200  can include one or more sensor interfaces  252  for communicating with interfaces  262  of sensors on buffer conveyor subassembly  114  and spur conveyor subassembly  116 . For example, controller  200  can include one sensor interface  252  for communicating with interface  260  of sensor  166  on buffer conveyor subassembly  114 , one interface  252  for communicating with an interface  278  of an optional sensor  276  configured to determine whether a carrier is present at position  154 , one interface  252  for communicating with an interface  282  of an optional sensor  280  configured to determine the orientation of diverter  150 , and one interface  252  for communicating with an interface  284  of sensor  148 . 
     Controller  200  also includes one or more power outputs  254 . For example, controller  200  can include four power outputs  254 . One power output  254  supplies power to a logic power input  256  of conveyor subassembly  114 . One power output  254  supplies power to drive assembly  172  that moves the track defining input and output portions  146  and  162  of buffer conveyor subassembly  114 . One power output  254  that supplies power to a power input  268  of optional stop unit  266  of buffer conveyor subassembly  114 . And one power output  254  that supplies power to power input  274  of gripper  188 . 
     Any one of the above described components can be omitted from controller  200  or modified based upon the design of buffer conveyor subassembly  114  and spur conveyor subassembly  116 . 
     As shown in  FIG. 15 , buffer conveyor subassembly  114  can include a CAN interface  258  in some embodiments. 
     In some embodiments, the controller of host conveyor assembly  102 , the controller for processing instrument  104 , and the controller for assay instrument  108  can be structured similar to the above described controller  200 . 
     Lab information system  223  manages patient and laboratory information. In some embodiments, lab information system  223  includes a server or host computer having a database, and application software for receiving, storing, and processing patient and laboratory information. In some embodiments, lab information system  223  generates a schedule for processing samples within sample containing receptacles  105  introduced within lab automation system  100  using processing instrument  104  and one or more of assay instruments  108 . For example, lab information system  223  can generate a schedule for processing samples within sample containing receptacles  105  introduced within lab automation system  100  that optimize the use of reagents by processing instrument  104  and assay instruments  108 , optimize the use (increase the throughput or ensure periods of instrument availability to run random access assays) of processing instrument  104  and assay instruments  108 . Lab information system  223  can also generate a schedule for samples within sample containing receptacles  105  introduced within lab automation system  100  that route the samples to the appropriate assay instrument  108  depending on the type of assay to be performed or the type of analyte to be discriminated. According to the generated schedule, lab automation system  100  routes carriers  101  to the appropriate one of assay instruments  108   a ,  108   b , and  108   c.    
     In some embodiments (for example, any of the embodiments of  FIGS. 11-13 ), controller  200  of intermediate conveyor subassembly  133  communicates various information to the controller of the respective assay instrument  108  using communication link  218 . For example, controller  200  can communicate one or more of the following types of information to and from the controller of assay instrument  108 : (1) the status of assay instrument  108  (e.g., whether assay instrument  108  is (a) idle, (b) ready for processing a sample from processing receptacle  103  coupled to a carrier  101  at processing position  154 , (c) processing, or (d) in failure state), (2) the status of intermediate conveyor assembly  133  (e.g., whether intermediate conveyor assembly  133  is (a) idle, (b) whether input portion  146  of buffer conveyor subassembly  114  has carriers  101  for transferring to spur conveyor subassembly  116 , (c) whether buffer conveyor subassembly  114  is transferring carriers  101  to spur conveyor subassembly  116 , or (d) whether intermediate conveyor assembly  133  is in failure state); (3) the status of processing position  154  in assay instrument  108  (e.g., whether processing position  154  is (a) empty, (b) occupied by a carrier  101  having an unprocessed (not yet aspirated) processing receptacle  103 , or (c) occupied by a carrier  101  having a processed (already aspirated) processing receptacle  103 ); (4) the number of carriers  101  in input portion  146  of buffer conveyor subassembly  114 ; (5) the number of carriers  101  in output portion  162  of buffer conveyor subassembly  114 ; (6) the number of carriers  101  output portion  162  of buffer conveyor subassembly  114  can receive from spur conveyor subassembly  116  before being full; (7) information read by sensor  156  from carrier  101 , receptacle  103 , or both, at processing position  154 , for example, an identifier read from an RFID tag on carrier  101 ; (8) information read by sensors  144  or  148  from carrier  101 , receptacle  103 , or both, at positions  141  or  147 , for example, an identifier read from an RFID tag on carrier  101 ; (9) a request or confirmation of a new carrier  101  being positioned at processing position  154 ; and (10) a request or confirmation of whether a receptacle  103  coupled to a carrier  101  is not be processed at processing position  154 . 
     In some embodiments (for example, any of the embodiments of  FIGS. 11-13 ), controller  200  of intermediate conveyor subassembly  133  communicates various information to the controller of host conveyor assembly  102  using communication link  216 . Communication link  216  can be CAN, RS485, RS422, USB, or Ethernet communication interfaces. For example, the following information can be communicated between controller  200  and the controller of host conveyor assembly  102 : (1) the status of host conveyor assembly  102  (e.g., whether host conveyor assembly  102  is (a) idle or (b) in a failure state); (2) the status of intermediate conveyor assembly  133  (e.g., (a) whether intermediate conveyor assembly  133  is idle, (b) whether input portion  146  of buffer conveyor subassembly  114  is full, (c) whether a carrier  101  is on output portion  162  of buffer conveyor subassembly  114 , or (d) whether intermediate conveyor assembly  133  is in a failure state); (3) the number of carriers  101  on input portion  146  of buffer conveyor subassembly  114 ; (4) the number of carriers  101  that input portion  146  of buffer conveyor subassembly  114  can receive from host conveyor assembly  102  before being full; (5) the number of carriers  101  on output portion  162  of buffer conveyor subassembly  114 ; (6) information read by sensors  146  or  148  from carrier  101 , receptacle  103 , or both, at positions  141  or  147 , for example, an identifier read from an RFID tag on carrier  101 ; (7) information read by sensor  156  from carrier  101 , receptacle  103 , or both, at processing position  154 , for example, an identifier read from an RFID tag on carrier  101 ; (8) a request or confirmation of a carrier  101  being transported to buffer conveyor subassembly  114  from host conveyor assembly  102 ; and (9) a request or confirmation of a carrier  101  being transferred from buffer conveyor subassembly  114  to host conveyor assembly  102 . 
     E. Exemplary Embodiments of Assay Instruments  108   
     In some embodiments, one or more of assay instruments  108  are each configured to perform one or more assays on samples contained within cavities defined by assay receptacles  160 . For example, the one or more assay instruments  108  can be configured to perform one or more assays that determine the presence of an analyte (for example, a biological analyte such as a pathogenic organism (e.g., bacterium, fungus, or protozoan) or virus) in a sample. In some embodiments, these assays can include performing nucleic acid amplification reactions on the samples. Exemplary nucleic acid amplification reactions include polymerase chain reactions, transcription-based amplification reactions, strand displacement amplification reactions, and ligase chain reactions. In other embodiments, assays can include, for example, nucleic acid detection immunoassays, immunoassays, and chemical assays. 
     In some embodiments, one assay instrument  108 , for example, assay instrument  108   a , performs one assay, and another assay instrument  108 , for example, assay instrument  108   b  or  108   c  performs a different assay. 
     For example, assay instrument  108   a  can perform a first assay on samples in assay receptacles  160  that determines the presence of a first type of analyte (e.g., antibodies, antigens, nucleic acids, toxins, or other chemicals), while another assay instrument  108   b  or  108   c  is configured to perform a different assay that determines the presence of a second type of analyte different than the first type of analyte. For example, one assay instrument  108  can perform an assay configured to detect the presence of a certain nucleic acid, while another assay instrument  108  performs a different assay to detect the presence of a certain antibody. 
     In some embodiments, the targeted analyte indicates that a particular bacterium, fungus, protozoan, or virus is present in the sample. In some embodiments, one assay instrument  108  is configured to perform an assay that detects the presence of a first analyte—the presence of which indicates that a particular bacterium, fungus, protozoan, or virus is present in the sample—while another assay instrument  108  is configured to perform a different assay that detects the presence of a different analyte—the presence of which indicates that a different bacterium, fungus, protozoan, or virus is present in the sample. For example, one assay instrument  108  can perform an assay configured to detect the presence of an analyte, the presence of which indicates that a specific virus, for example, a hepatitis C virus (HCV), is present in the sample. And another assay instrument  108  performs a different assay to detect the presence of a different analyte—the presence of which indicates that a different virus, for example, a human immunodeficiency virus (HIV), is present in the sample. 
     In yet another example, one assay instrument  108  is configured to perform one assay that includes performing a first type of nucleic acid amplification reaction on a sample contained within assay receptacle  160 , while another assay instrument  108  is configured to perform a different assay that includes performing a different type of nucleic acid amplification reaction. For example, one assay instrument  108  can perform an assay that includes subjecting samples to conditions (e.g., adding reagent(s) and exposing samples to certain temperature(s) including thermocycling or isothermal conditions) that promote a certain type of nucleic acid amplification reactions, for example, a polymerase chain reaction, while another assay instrument  108  can perform a different assay that includes subjecting samples to conditions (e.g., adding reagent(s) and exposing samples to certain temperature(s) including thermocycling or isothermal conditions) that promote a different type of nucleic acid amplification reaction, for example, a transcription-based amplification reaction. Or for example, one assay instrument  108  performs one assay that includes performing real-time amplification reactions that can be used to determine the presence and amount of a target nucleic acid in a sample in assay receptacle  160 , while another assay instrument  108  performs a different assay that includes performing “end-point” amplification assays. Real-time amplification assays can be used to determine the presence and amount of a target nucleic acid in a sample which, by way of example, is derived from a pathogenic organism (e.g., bacterium, fungus, or protozoan) or virus. Real-time amplification assays are often referred to as quantitative assays. By determining the quantity of a target nucleic acid in a sample, a practitioner can approximate the amount or load of the organism or virus in the sample. Real-time amplification assays can also be used to screen blood or blood products intended for transfusion for blood borne pathogens, such as hepatitis C virus (HCV) and human immunodeficiency virus (HIV). Real-time assays can also be used to monitor the efficacy of a therapeutic regimen in a patient infected with a pathogenic organism or virus, or that is afflicted with a disease characterized by aberrant or mutant gene expression. Real-time amplification assays can also be used for diagnostic purposes, as well as in gene expression determinations. Exemplary assay instruments  108  for performing real-time amplification assays are disclosed by Macioszek et al. in U.S. Pat. No. 7,897,337. 
     In end-point amplification assays, the presence of amplification products containing the target sequence or its complement is determined at the conclusion of an amplification procedure. End-point amplification assays are sometimes referred to as qualitative assays because such assays do not indicate the amount of a target analyte present, but provide a qualitative indication regarding the presence of the target analyte. Exemplary assay instruments  108  for end-point detection are disclosed by Ammann et al. in U.S. Pat. No. 6,335,166. 
     In some embodiments, one or more of assay instruments  108  are configured to perform assays that capture, amplify, and detect nucleic acids from target organisms in samples. 
     In some embodiments, assay instruments  108  are configured to perform a target capture process that isolates nucleic acid of the target analyte (e.g., virus, bacterium, fungus, protozoan, mammalian cells, etc.) and purifies nucleic acid for amplification. U.S. application Ser. No. 12/465,323, filed May 13, 2009, to Becker et al. describes various exemplary target capture processes. Assay instruments  108  can be configured to lyse the target analyte, which can be in a variety of biological matrices (including urine and blood), with target capture reagents (“TCR”), whereby the nucleic acid is released. 
     In some embodiments, assay instruments  108  are configured to perform assays on a sample in a single assays receptacle  160  using common reagents as a one-step process. In some embodiments, assay instruments  108  can detect low-abundance nucleic acid, and use specific controls to obtain quantitative results. 
     In some embodiments, assay instrument  108  can include a thermal cycler (not shown) for exposing the sample in assay receptacle  160  to temperatures that are cycled between two or more different temperatures. 
     In some embodiments, assay instruments  108  are each configured to perform a plurality of different assays, for example, different molecular assays, including nucleic acid based amplification assays, nucleic acid detection immunoassays, immunoassays, and/or chemical assays, on a plurality of samples. In some embodiments, assay instruments  108  are each configured perform different target nucleic acid amplification reactions. For example, one assay instrument  108  is configured to perform a first target nucleic acid amplification reaction on a first subset of a plurality of samples, and perform a second, different target nucleic acid amplification reaction on a second subset of the plurality of samples. 
     In some embodiments, each assay instrument  108  includes a first module configured to perform at least one of the steps of a first target nucleic acid amplification reaction, and a second module configured to perform at least one of the steps of a second target nucleic acid amplification. 
     In some embodiments, each assay instrument  108  includes various devices configured to receive one or more assay receptacles  160 , within each of which is performed one or more steps of a multi-step assay, for example, a nucleic acid test (NAT) designed to detect a virus or organism (e.g., bacterium, fungus, or protozoan). Each assay instrument  108  can be configured to perform one or more of the following processes: adding substances such as sample fluid, reagents (e.g., target capture reagents used in the target capture process to isolate the target nucleic acid (e.g., magnetically responsive particles with immobilized polynucleotides, polynucleotide capture probes, and reagents sufficient to lyse cells containing the targeted nucleic acids), amplification reagents used in nucleic acid amplification reactions to amplify the target nucleic acid or portion thereof (e.g., oligonucleotides for use in producing one or more detectable amplicons for the target nucleic acid), buffers, oils, labels (i.e., a moiety or compound that is detected or leads to a detectable signal such as luminescent or fluorescent compounds), probes (e.g., nucleic acid oligomers that fully or partially hybridize to a target sequence in a nucleic acid, or in an amplicon containing the target sequence or its complement, under conditions that promote hybridization (e.g., under stringent hybridization conditions) to allow detection of the target sequence or amplicon), or any other reagent) and/or removing substances from an assay receptacle  160 ; agitating an assay receptacle  160  to mix the contents thereof; maintaining and/or altering the temperature of the contents of an assay receptacle  160 ; heating or chilling the contents of an assay receptacle  160 ; altering the concentration of one or more components of the contents of an assay receptacle  160 ; separating or isolating constituent components of the contents of an assay receptacle  160 ; detecting an electromagnetic signal emission (e.g., light) from the contents of an assay receptacle  160 ; halting an on-going reaction in an assay receptacle  160 ; deactivating a nucleic acid in an assay receptacle  160  from further amplification, or any combination thereof. 
     In some embodiments, each assay instrument  108  can include an assay receptacle  160  input device that includes structure for receiving and holding one or more empty an assay receptacle  160  before assay receptacles  160  are used for performing one or more process steps of an assay, for example, a nucleic acid test. The receptacle input device may comprise a compartment, for example, a drawer or cabinet. 
     In some embodiments, each assay instrument  108  includes one or more bulk reagent container compartments configured to store one or more bulk containers that hold bulk reagents or hold waste material. 
     In some embodiments, each assay instrument  108  includes a first bulk reagent container compartment configured to store at least one bulk container that holds a nucleic acid amplification reagent, and a separate second bulk reagent container compartment configured to store at least one bulk container that holds a sample preparation reagent, for example, a target capture reagent. In some embodiments, each assay instrument  108  includes a bulk reagent container compartment that stores both a bulk container that holds a nucleic acid amplification reagent and a bulk container that holds a sample preparation reagent, for example, a target capture reagent. 
     Each assay instrument  108  can also include a manual sample input bay configured to manually receive and hold processing receptacles  103  containing samples. 
     Each assay instrument  108  can include at least one automated pipettor  158  configured to transfer fluids, for example, sample fluids, reagents, bulk fluids, waste fluids, etc., to and from assay receptacles  160 , other receptacles, and processing receptacles  103  coupled to carriers  101  at processing position  154  within assay instrument  108 . Pipettor  158  can be configured for controlled, automated movement and access to the assay receptacles  160 , bulk receptacles holding reagents, processing receptacles in the sample input bay, and processing receptacles  103  coupled to carriers  101  at processing position  154 . 
     In some embodiments in which each assay instrument  108  is configured to perform a nucleic acid test, reaction reagents contained within assay instrument  108  may comprise target capture reagents, lysis reagents (e.g., detergents such as lithium lauryl sulfate and sodium dodecyl sulfate), nucleic acid amplification reagents (e.g., the primers, polymerases, nucleoside triphosphates, and salts needed for an amplification), and/or labels. 
     In some embodiments, each assay instrument  108  includes temperature ramping stations configured to hold one or more assay receptacles  160  in an environment that is maintained at higher or lower than ambient temperatures so as to raise or lower the temperature of the contents of the receptacles. In some embodiments, no reaction is performed on a sample at the temperature ramping station. In some embodiments, the temperature ramping station is used to raise or lower the temperature to the approximate temperature of another station in assay instrument  108  where a subsequent process step will be performed. 
     In some embodiments, each assay instrument  108  also includes one or more heater modules configured to receive a plurality of assay receptacles  160  and maintain the receptacles in an elevated temperature environment. 
     Also, in some embodiment in each assay instrument  108  is configured to perform a nucleic acid test, each assay instrument  108  can include sample-processing components, such as magnetic separation wash stations configured to isolate and/or separate a target nucleic acid immobilized on target capture reagent from the remaining contents of assay receptacle  160 . 
     In some embodiments, each assay instrument  108  can further include chilling modules configured to receive one or more assay receptacles  160  and hold the receptacles in a lower than ambient temperature environment so as to reduce the temperature of the contents of the receptacles. 
     And in some embodiments, each assay instrument  108  can include a detector configured to receive an assay receptacles  160  and detect signals (e.g., optical signals) emitted by the contents of the assay receptacles  160 . In one implementation, the detector includes a luminometer for detecting luminescent signals emitted by the contents of an assay receptacles  160  and/or a fluorometer for detecting fluorescent emissions. Each assay instrument  108  can also include one or more signal detecting devices, such as fluorometers, coupled to one or more of the incubators that are configured and controlled to detect, for example, at specified, periodic intervals, signals emitted by the contents of the assay receptacles  160  contained in the incubator while a process, such as nucleic acid amplification, is occurring within the reaction receptacles. 
     Each assay instrument  108  can include a receptacle transfer device configured to transport assay receptacles  160  to one or more of the incubators, load stations, temperature ramping stations, wash stations, and chilling modules contained within the housing of assay instrument  108 . 
     In some embodiments, each assay instrument  108  is configured to perform an assay that includes the nucleic acid amplification reaction and, in some embodiments, includes measuring fluorescence in real-time (i.e., as the amplification reaction is occurring). Each assay instrument  108  can include a thermal cycler/signal detector, a centrifuge, magnetic elution stations, and reagent pack loading stations. In some embodiments, automated pipettor  158  is configured to have access to the magnetic elution stations and the reagent pack loading stations. 
     In some embodiments, the bulk reagents within the bulk reagent containers within assay instrument  108  can include a sample preparation reagent (e.g., target capture reagent (TCR), a wash solution, an elution reagent, or any other sample preparation reagent), a reconstitution reagent, or any other required bulk reagent. In some embodiments, the bulk reagent containers hold a quantity of the bulk reagent sufficient to perform between about 50 to 2,000 assays. In some embodiments, the bulk reagents are for performing isothermal nucleic acid amplification reactions. 
     In some embodiments, each assay instrument  108  can be configured to perform two or more assays that include nucleic acid amplification reactions that require different reagents, including one or more unit-dose reagents—reagents that are unitized into an amount or concentration sufficient to perform one or more steps of a single assay for a single sample. On such assay instrument  108  is described in U.S. application Ser. No. 14/213,900, filed Mar. 14, 2014, to Buse et al. 
     Results of the assays performed by each of assay instruments  108  may be displayed on an instrument user interface of assay instrument  108  communicated to laboratory information system  223 . 
     F. Exemplary Embodiments of Carrier  101   
     As used in this application, a “carrier” refers to any device that is configured to operatively couple to at least one receptacle (for example, a sample containing receptacle, a processing receptacle, or any other receptacle) for transporting the at least once receptacle within system  100 . Carriers  101  are configured to maintain the orientation of the respective receptacles coupled thereto as the carriers are transported throughout the system. For example, in some embodiments, carriers  101  are pucks having a cylindrical portion defining a recess configured to receive a portion the receptacle. In some puck embodiments, carrier  101  includes a clamping device configured to apply a retaining force to the receptacle placed within the recess of carrier  101  such that the receptacle is retained within the carrier  101 . 
       FIGS. 17 and 18  illustrate an embodiment of carrier  101 . As shown in  FIG. 17 , carrier  101  includes a cylindrical main body  286  having a top end portion  288  and a bottom end portion  290 . In other embodiments, main body  286  can have non-cylindrical shapes. 
     In some embodiments, main body  286  is sized to fit on each of intermediate conveyor assembly  106 , host conveyor assembly  102 , and intermediate conveyor assemblies  133 A- 133 C. When carrier  101  is placed on intermediate conveyor assembly  106 , host conveyor assembly  102 , or intermediate conveyor assemblies  133 A- 133 C, bottom end portion  290  is adjacent, for example, a movable track of respective intermediate conveyor assembly  106 , host conveyor assembly  102 , and intermediate conveyor assemblies  133 A- 133 C. 
     In some embodiments, top end portion  288  defines a recess  292 , which can be circular in some embodiments. Recess  292  is configured to receive at least one movable retaining member  294 . For example, as shown in  FIG. 17 , circular recess  292  is configured to receive three movable retaining members  294 . The retaining members  294  each have annular sector shape (when viewed in plan) and collectively form an annulus defining an interior recess portion  296 , which can be circular in some embodiments, configured to receive a portion, for example, a bottom portion of a processing receptacle  103  to couple the processing receptacle  103  to the carrier  101 . In some embodiments, each retaining member  294  includes a tapered surface  308  that aligns receptacle  103  with the center of recess portion  296  when receptacle  103  is being inserted in recess portion  296 . In other embodiments, carrier  101  can include less than three or more than three movable retaining members  294 . And in other embodiments, retaining members  294  can have other non-annular sector shapes when viewed in plan. In yet other embodiments, retaining members  294  can define an interior recess portion  296  that has a non-circular shape. In some embodiments, the depth of recess portion  296  and the placement of a machine readable label, for example, a barcode, on receptacle  103  are such that when the bottom portion of a receptacle  103  is inserted within recess portion  296 , the machine readable label on receptacle  103  is not obstructed by any portion carrier  101  and such that a sensor, for example, a barcode reader, can read the label on receptacle  103 . 
     In some embodiments, carrier  101  includes one or more retaining fasteners (for example, as shown in  FIGS. 17 and 18 , a screw and corresponding washer) configured to secure retaining members  294  within recess  292  of carrier  101 . In some embodiments, retaining fasteners are stainless steel or a non-ferrous material so as to not interfere with any RFID tag on carrier  101  or receptacle  103 . Correspondingly, in some embodiments, all components of carrier  101  are composed of a non-ferrous material so as to not interfere with any RFID tag on carrier  101  or receptacle  103 . 
     Retaining members  294  are biased toward a center of recess portion  296  such that each retaining member  294  applies a force to a bottom portion of processing receptacle  103  inserted in recess portion  296 , generating an axial retaining force (e.g., via friction) that secures receptacle  103  to carrier  101 . In some embodiments, the magnitude of the applied force to the bottom portion of processing receptacle  103  is sufficient to generate an axial retaining force that secures receptacle  103  to carrier  101  as carrier  101  is transported by any one of intermediate conveyor assembly  106 , host conveyor assembly  102 , and intermediate conveyor assemblies  133 A- 133 C. In some embodiments, the magnitude of the applied force to the bottom portion of processing receptacle  103  is not so great as to squeeze receptacle  103  upward and out of recess portion  296 . In some embodiments, the sum of the axial retaining forces generated by retaining members  294  and the axial retaining forces generated by gripper  188  via second portions  193  of prongs  189  (as described above) is equal to or greater than any axial force applied to receptacle  103  in the opposite direction of the generated retaining forces (for example, a force applied to receptacle  103  as the distal end of pipettor  158  is removed from receptacle  103 ). In some embodiments, this sum of axial retaining forces applied to receptacle  103  is equal to or greater than about four pounds. In some embodiments, this sum of axial retaining forces applied to receptacle  103  is equal to or greater than about 6 pounds. 
     In some embodiments, carrier  101  includes a biasing device that biases retaining members  294  toward the center of recess portion  296  to apply the forces to the bottom portion of processing receptacle  103  inserted in recess portion  296 . For example, in some embodiments, each retaining member  294  can define one or more periphery grooves  304  configured to receive respective one or more garter springs  306  that bias each retaining member  294  toward the center of recess portion  296  to apply forces to the bottom portion of processing receptacle  103  inserted in recess portion  296 . 
     In some embodiments, movable retaining members  294  have a radial stroke such that inner recess portion  296  can have a varying size that accommodates receptacles  103  of varying diameters. For example, in some embodiments, inner recess portion  296  can accommodate receptacles  103  having diameters varying from about 8 mm to about 20 mm, including receptacles  103  having a diameter of 12 mm or 16 mm. 
     In some embodiments, main body  286  defines one or more periphery, circumferential grooves. For example, as shown in  FIGS. 17 and 18 , main body  286  defines a lower groove  300 . Lower groove  300  can be configured to mate with corresponding protrusions on any one of intermediate conveyor assembly  106 , host conveyor assembly  102 , and intermediate conveyor assemblies  133 A- 133 C to prevent carrier  101  and the receptacle  103  coupled thereto from tipping over as carrier  101  is transported along the respective conveyor assembly. For example, one or more guide rails of intermediate conveyor assembly  106 , host conveyor assembly  102 , and/or intermediate conveyor assemblies  133 A- 133 C can define a protrusion that is received within lower groove  300  of carrier  101  as carrier  101  is transported along the respective conveyor assembly. When the protrusion on the guide rail is received within lower groove  300  of carrier  101  the carrier is substantially prevented from tipping over relative to the track(s) of the respective intermediate conveyor assembly  106 , host conveyor assembly  102 , and/or intermediate conveyor assemblies  133 A- 133 C, thereby also preventing receptacle  103  coupled thereto from tipping over. 
     Main body  286  can also define a second, upper groove  302 . Upper groove  302  can be configured to mate with corresponding protrusions on gripper  188  to hold carrier  101  down as a distal end of an aspirator  158  is removed from receptacle  103  when carrier  101  is at the processing position  154  of assay instrument  108 . For example, first portion  191  of each prong  189  of gripper  188  can form a protrusion that mates with groove  302  of carrier  101  to hold carrier  101  down to base  186  within spur conveyor  116  of intermediate conveyor assembly  133 . 
     As shown in  FIGS. 18, 29, 30, and 37 , upper and lower grooves  301  and  302  can have various shapes, sizes, and orientations. 
     In some embodiments, bottom end portion  290  defines a recess  310  configured to receive one or more components. For example, recess  310  can be shaped to closely receive one or more RFID tags or any other types of transponders. In some embodiments, recess  310  includes a first portion  312  shaped to receive first type of component and a second portion  314  shaped to receive a different type of component. For example, as shown in  FIG. 17 , first portion  312  can have a cylindrical shape configured to closely receive an RFID tag that operates at one frequency, and second portion  314  can have a rectangular shape configured to closely receive a different type of RFID tag that operates at a different frequency. As shown in  FIG. 17 , second portion  314  of recess  310  can extend from a surface defining first portion  312  of recess  310  toward top end portion  288  of main body  286 . In some embodiments, the center of first portion  312  of recess  310  and the center of second portion  314  of recess  310  are coaxial with each other and, in some embodiments, are coaxial with the center of recess portion  296  that receives receptacle  103 . 
     This application also discloses new, original, and ornamental designs for a carrier  101 , reference being had to, for example, the designs of  FIGS. 27-37 , forming a part thereof. In  FIGS. 27-37 , the broken lines show portions of the sample carrier that form no part of the disclosed designs. 
     2. Exemplary Embodiments of Use and Sample Processing Methods 
     Embodiments of processing samples using one or more of processing instrument  104 , intermediate conveyor assembly  106 , host conveyor assembly  102 , intermediate conveyor assemblies  133 , and assay instruments  108  will now be described. In some embodiments, processing instrument  104  reads information (e.g., an identifier) from carrier  101 , processing receptacle  103 , or both, using, for example, sensor  138 , and the controller of processing instrument  104  transmits the read information, for example, an identifier, of carrier  101 , processing receptacle  103 , or both, to lab information system  223  via communication link(s)  228 . Lab information system  223  can then associate the sample dispensed into receptacle  103  with the identifier on carrier  101 , receptacle  103 , or both, read by a sensor. Afterwards, intermediate conveyor assembly  106  can transport the carrier  101  and processing receptacle  103  coupled thereto from processing instrument  104  to host conveyor assembly  102 . These steps can then be repeated for one or more additional processing receptacles  103  and carriers  101 . 
     As shown in  FIG. 1 , host conveyor assembly  102  transports the carriers  101  and receptacles  103  coupled thereto (which were received from intermediate conveyor assembly  106 ) along first portion  118  toward assay instrument  108   a . As carriers  101  pass sensor  144 , sensor  144  reads information from carrier  101 , receptacle  103 , or both, and transmits a signal to a controller of host conveyor assembly  102  that includes the read information. The controller of host conveyor assembly  102  can then determine whether the read information, for example, an identifier, is associated with a first sample on which assay instrument  108   a  is scheduled to perform an assay on the sample in the receptacle  103 . This determination can be based on information stored in the laboratory information system  223 . If the read information from carrier  101  or receptacle  103  passing sensor  144  is associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, the controller of host conveyor assembly  102  then sends a control signal to diverter  142   a  to divert the respective carrier  101  from host conveyor assembly  102  to input portion  146  of buffer conveyor subassembly  114  of intermediate conveyor assembly  133   a . If the read information from carrier  101  or receptacle  103  passing sensor  144   a  is not associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, the controller of host conveyor assembly  102  adjusts the control signal transmitted to diverter  142   a , which then divert the respective carrier  101  to a downstream portion  145   a  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133   a  and assay instrument  108   a . Host conveyor assembly  102  then continues to transport the carrier  101  toward the next assay instrument  108   b.    
     As the next carrier  101  passes sensor  144   a , sensor  144   a  reads information from that carrier  101 , receptacle  103  coupled to that carrier  101 , or both, and transmits a signal to the controller of host conveyor assembly  102  that includes the read information. The controller of host conveyor assembly  102  can then determine whether the read information, for example, an identifier, is associated with a sample on which assay instrument  108   a  is scheduled to perform an assay based on information stored in the laboratory information system  223 . If the read information is associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, the controller of host conveyor assembly  102  then sends a control signal to diverter  142   a  to divert the next carrier  101  from host conveyor assembly  102  to input portion  146   a  of buffer conveyor subassembly  114   a  of intermediate conveyor assembly  133   a . If the read information from the subsequent carrier  101  is not associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, the controller of host conveyor assembly  102  adjusts the control signal transmitted to diverter  142   a  to divert the subsequent carrier  101  to a downstream portion  145   a  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133   a  and assay instrument  108 . Host conveyor assembly  102  then continues to transport the subsequent carrier  101  toward the next assay instrument  108   b.    
     Host conveyor assembly  102  can divert a plurality of carriers  101  to input portion  146   a  of buffer conveyor subassembly  114   a  until input portion  146   a  of buffer conveyor subassembly  114  is full. At that point, the controller of host conveyor assembly  102  will continue to divert carriers  101  to downstream portion  145   a  of host conveyor assembly  102  regardless of whether the sample contained within receptacle  103  coupled to carrier  101  is scheduled for an assay to be performed by assay instrument  108   a  until space is available on input portion  146   a  of buffer conveyor subassembly  114   a  to accept additional carriers  101 . 
     Once a carrier  101  is diverted from host conveyor assembly  102  to input portion  146   a  of buffer conveyor subassembly  114   a , the controller of host conveyor assembly  102  provides a notification to controller  200   a  of intermediate conveyor assembly  133   a  that a carrier  101  was diverted. And in some embodiments, the controller of host conveyor assembly  102  transmits information about the diverted carrier  101 , for example, an identifier of the carrier  101 , receptacle  103 , or both, to controller  200   a.    
     Once a predetermined minimum number of carriers  101  have been queued on input portion  146   a , controller  200   a  can notify the controller of assay instrument  108   a  that the predetermined minimum number of carriers  101  and, thus, samples in processing receptacles  103  are available for processing by assay instrument  108   a . In some embodiments, the predetermined minimum number of carriers  101  is at least five carriers  101 . In other embodiments, the predetermined minimum number of carriers  101  is less than five. In some embodiments, the predetermined minimum number of carriers  101  equals the number of cavities defined by a signal assay receptacle  160 . For example, if a single assay receptacle  160  defines five cavities for receiving five samples, the predetermined minimum number of carriers equals five. 
     Input portion  146   a  transports diverted carriers  101  towards position  147  on buffer conveyor subassembly  114   a  and queues a plurality of carriers  101  until assay instrument  108   a  is ready to start processing samples contained in receptacles  103  coupled to carriers  101 . In some embodiments, as a carrier  101  on buffer conveyor subassembly  114   a  passes sensor  148   a , sensor  148   a  reads information from the passing carrier  101 , receptacle  103 , or both, and transmits a signal to controller  200   a  of intermediate conveyor assembly  133   a  that includes the read information. Controller  200   a  of intermediate conveyor assembly  133   a  can then determine whether the read information, for example, an identifier, is associated with or matches the information transmitted from the controller of host conveyor assembly  102  to intermediate conveyor assembly  133   a  about the respective diverted carrier  101 . If the read information matches or is associated with the transmitted information, controller  200   a  of intermediate conveyor assembly  133   a  sends a control signal to diverter  150   a  to divert the respective carrier  101  from input portion  146   a  of buffer conveyor subassembly  114   a  to spur conveyor subassembly  116   a . If the read information does not match or is not associated with the transmitted information, controller  200   a  of intermediate conveyor assembly  133   a  adjusts the control signal to diverter  150   a  to divert the carrier  101  from input portion  146   a  of buffer conveyor subassembly  114   a  directly to output portion  162   a  of buffer conveyor subassembly  114   a , bypassing spur conveyor subassembly  116   a.    
     After being transferred to spur conveyor subassembly  116   a  of intermediate conveyor assembly  133   a , spur conveyor subassembly  116   a  transports the carrier  101  to processing position  154   a  within assay instrument  108   a . For example, gripper  188  clamps the carrier  101  at position  153   a , and moves towards processing position  154   a  until the carrier  101  is at position  154   a . Sensor  156   a  can then read information from the carrier  101 , receptacle  103  coupled thereto, or both, when carrier  101  is at processing position  154   a . Sensor  156   a  can also transmit a signal to controller  200   a  of intermediate conveyor assembly  133  that includes the read information. Controller  200   a  of intermediate conveyor assembly  133   a  can then determine whether the read information, for example, an identifier, is associated with a sample on which assay instrument  108   a  is scheduled to perform an assay. This determination can be based on information stored in the laboratory information system  223 . In some embodiments, another sensor of spur conveyor subassembly detects whether carrier is indeed at position  154   a . If the read information is associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, controller  200   a  then sends a notification to the communication interface of the controller of assay instrument  108  that processing of the sample within the processing receptacle  103  coupled to carrier  101  located at processing position  154  can begin. As explained above, pipettor  158   a  of assay instrument  108   a  can aspirate at least a portion of a sample from receptacle  103  coupled to carrier  101  at processing position  154   a , and pipettor  158   a  can subsequently dispense the aspirated sample portion into a cavity defined by assay receptacle  160   a . After assay instrument  108   a  completes the processing of samples within processing receptacle  103  coupled to carrier  101  at processing position  154   a , the communication interface of the controller of assay instrument  108  sends a notification to controller  200   a  of intermediate conveyor assembly  133   a  that processing is complete, and spur conveyor spur conveyor subassembly  116   a  then transports the carrier  101  away from processing position  154   a  and back to position  153  on spur conveyor subassembly  116   a . Diverter  150   a  can then transport the carrier  101  to output portion  162   a  of buffer conveyor subassembly  114   a . In some embodiments, the total time it takes to (1) transport carrier  101  from position  153   a  to processing position  154   a  using spur conveyor subassembly  116   a , (2) process the sample contained with the sample receptacle  103  coupled to the carrier  101  at position  154   a  (i.e., aspirate at least a portion of a sample from receptacle  103  using automated pipettor  158   a  of assay instrument  108   a ), and (3) transport the carrier  101  from processing position  154  to position  153  using spur conveyor subassembly  116  takes less than or equal to about 1 minute. 
     If the information read by sensor  156  is not associated with a sample on which assay instrument  108   a  is scheduled to perform an assay, controller  200   a  notifies the communication interface of the controller of assay instrument  108  that processing should not begin, and spur conveyor subassembly  116   a  transports the carrier  101  back to position  153   a . Diverter  150   a  then transports the carrier to output portion  162   a  of buffer conveyor subassembly  114   a . The steps of transporting a carrier  101  from position  153   a  to processing position  154   a  using spur conveyor subassembly  116 , processing the sample contained with the sample receptacle  103  coupled to the carrier  101  at position  154   a , and transporting the carrier  101  from processing position  154   a  to position  153   a  using spur conveyor subassembly  116   a  is repeated as long as long as minimum number of carriers  101  are on the input portion  146   a  of buffer conveyor subassembly  114   a , the output portion  162   a  of buffer conveyor subassembly  114   a  is not full, and consumables, waste space, and reagents are available within assay instrument  108   a.    
     Output portion  162   a  of buffer conveyor subassembly  114   a  transports the carrier  101  received from spur conveyor subassembly  116   a  to position  167   a . When sensor  166   a  detects the presence of a carrier  101  at position  167   a , diverter  164   a  is actuated and transports the carrier  101  back to host conveyor assembly  102 . 
     Host conveyor assembly  102  continues to transport the carriers  101  that were either bypassed by assay instrument  108   a  toward the next assay instrument  108   b  or received from output portion  162   a  of buffer conveyor subassembly  114   a  of intermediate conveyor assembly  133   a  toward the next assay instrument  108   b . As carriers  101  approach assay instrument  108   b  and pass sensor  144   b , sensor  144   b  reads information from the carriers  101 , receptacles  103 , or both, and sensor  144   b  transmits a signal to the controller of host conveyor assembly  102  that includes the read information. The controller of host conveyor assembly  102  then determines whether the read information, for example, an identifier, is associated with samples on which assay instrument  108   b  is scheduled to perform an assay based on information stored in the laboratory information system  101 . If this read information is associated with samples on which assay instrument  108   b  is scheduled to perform an assay, the controller of host conveyor assembly  102  then sends a control signal to diverter  142   b  to divert the respective carriers  101  from host conveyor assembly  102  to input portion  146   b  of buffer conveyor subassembly  114   b  of intermediate conveyor assembly  133   b . If the read information is not associated with samples on which assay instrument  108   b  is scheduled to perform an assay, the controller of host conveyor assembly  102  can adjust the control signal transmitted to diverter  142   b  to divert the respective carriers  101  to a downstream portion  145   b  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133   b  and assay instrument  108   b . Host conveyor then continues to transport the bypassed carriers  101  toward the next assay instrument  108   c.    
     The step of diverting carriers from host conveyor assembly  102  to input portion  146   b  of buffer conveyor subassembly  114   b  of intermediate conveyor assembly  133   b  can continue for subsequent carriers  101  passing sensor  144   b  until input portion  146   b  of buffer conveyor subassembly  114   b  is full. At that point, the controller of host conveyor assembly  102  will continue to divert carriers  101  to portion  145   b  of host conveyor assembly  102  regardless of whether the sample contained within receptacle  103  coupled to the carrier  101  is scheduled for an assay to be performed by assay instrument  108   b  until space is available on input portion  146   b  of buffer conveyor subassembly  114   b  to accept additional carriers  101 . In some embodiments, loading input portion  146   b  of buffer conveyor subassembly  114   b  continues until at least a predetermined minimum number of carriers, for example, five carriers  101 , have been queued on input portion  146   b . Once a minimum number of carriers  101  have been queued, controller  200   b  can notify the controller of assay instrument  108  that the predetermined minimum number of carriers  101  (and thus samples in processing receptacles  103 ) available for processing by assay instrument  108 . Once diverted to input portion  146   b  of buffer conveyor subassembly  114   b , the controller of host conveyor assembly  102  provides a notification to controller  200   b  of intermediate conveyor assembly  133   b  that a carrier  101  was diverted to input portion  146   b  and, in some embodiments, transmits information about the diverted carrier  101 , for example, an identifier of the carrier  101 , receptacle  103 , or both, to controller  200   b . Buffer conveyor subassembly  114   b  transports the carrier  101  toward position  147   b  on and queues the carrier. In some embodiments, as a carrier  101  on buffer conveyor subassembly  114   b  passes sensor  148   b , sensor  148   b  reads information from a respective carrier  101 , receptacle  103 , or both, and transmits a signal to controller  200   b  of intermediate conveyor assembly  133   b  that includes the read information. Controller  200   b  can then determine whether the read information, for example, an identifier, is associated with the information transmitted from the controller of host conveyor assembly  102  to intermediate conveyor assembly  133  about the diverted carrier  101 . If the read information matched the transmitted information, controller  200   b  of intermediate conveyor assembly  133   b  sends a control signal to diverter  150   b  to divert the respective carrier  101  from input portion  146   b  of buffer conveyor subassembly  114   b  to spur conveyor subassembly  116   b . If the read information does not match the transmitted information, controller  200   b  of intermediate conveyor assembly  133   b  adjusts the control signal to diverter  150   b  to divert the carrier  101  from input portion  146   b  of buffer conveyor subassembly  114   b  directly to output portion  162   b  of buffer conveyor subassembly  114   b , bypassing spur conveyor subassembly  116   b.    
     If a carrier  101  is diverted to spur conveyor subassembly  116   b  of intermediate conveyor assembly  133   b , spur conveyor subassembly  116   b  transports the carrier  101  to processing position  154   b  within assay instrument  108   b . For example, gripper  188  clamps the carrier  101  at position  153   b  and moves towards position  154   b  until the carrier  101  is at position  154   b . Sensor  156   b  can then read information from the carrier  101 , receptacle  103 , or both, when carrier  101  is at processing position  154   b  and transmits a signal to controller  200   b  of intermediate conveyor assembly  133   b  that includes the read information. Controller  200   b  can then determine whether the information read by sensor  144   b , for example, an identifier, is associated with a sample on which assay instrument  108   b  is scheduled to perform an assay. This determination can be based on information stored in the laboratory information system  223 . In some embodiments, another sensor of spur conveyor subassembly  116   b  detects whether carrier is indeed at position  154   b . If the read information is associated with a sample on which assay instrument  108   b  is scheduled to perform an assay, controller  200   b  then sends a notification to the communication interface of the controller of assay instrument  108   b  that processing of the sample within the receptacle  103  coupled to carrier  101  located at processing position  154   b  can begin. After assay instrument  108   b  completes the processing of the sample within processing receptacle  103  coupled to carrier  101  at processing position  154   b , the communication interface of the controller of assay instrument  108  sends a notification to controller  200   b  of intermediate conveyor assembly  133   b  that processing is complete, and spur conveyor subassembly  116   b  transports the carrier  101  back to position  153   b . Diverter  150   b  then transports the carrier  101  to output portion  162   b  of buffer conveyor subassembly  114   b.    
     If the information read by sensor  156   b  is not associated with a sample on which assay instrument  108   b  is scheduled to perform an assay, controller  200   b  notifies the communication interface of the controller of assay instrument  108   b  that processing should not begin, and spur conveyor subassembly  116   b  transports the carrier  101  back to position  153   b , and diverter  150   b  transfers the carrier  101  to output portion  162   b  of buffer conveyor subassembly  114   b . The step of transporting a carrier  101  from position  153   b  to processing position  154   b  using spur conveyor subassembly  116   b , processing the sample contained within the sample receptacle  103  coupled to the carriers  101  at position  154   b , and transporting the carrier  101  from processing position  154   b  to position  153   b  using spur conveyor subassembly  116   b  is repeated as long as (1) a predetermined minimum number of carriers  101  are on the input portion  146   b  of buffer conveyor subassembly  114   b , (2) the output portion  162   b  of buffer conveyor subassembly  114   b  is not full, and (3) consumables, waste space, and reagents are available within assay instrument  108   b.    
     Output portion  162   b  of buffer conveyor subassembly  114   b  transports the carriers  101  received from spur conveyor subassembly  116   b  to position  167   b . When sensor  166   b  detects the presence of a carrier  101  at position  167   b , diverter  164   b  is actuated and transports the carrier  101  back to host conveyor assembly  102 . 
     Host conveyor assembly  102  transports the carriers  101  either bypassed by assay instrument  108   b  or received from output portion  162   b  of buffer conveyor subassembly  114   b  toward the next assay instrument  108   c . As carriers  101  approach diverter  122 , sensor  126  detects the presence of a carrier  101  within a recess defined by diverter  122 , and the controller of host conveyor assembly  102  in communication with sensor  126  actuates diverter  122  to transfer the carrier  101  to second portion  120  of host conveyor assembly  102 . Second portion  120  of host conveyor assembly continues to transport carriers  101  toward assay instrument  108   c  and such that carriers  101  pass sensor  144   c . Sensor  144   c  reads information (e.g., an identifier) from the carriers  101 , receptacles  103 , or both, and transmits a signal to the controller of host conveyor assembly  102  that includes the read information. The controller of host conveyor assembly  102  then determines whether the read information, for example, an identifier, is associated with samples on which assay instrument  108   c  is scheduled to perform an assay. This determination can be based on information stored in the laboratory information system  223 . If this read information is associated with a sample on which assay instrument  108   c  is scheduled to perform an assay, the controller of host conveyor assembly  102  then sends a control signal to diverter  142   c  to divert the respective carrier  101  from host conveyor assembly  102  to input portion  146   c  of buffer conveyor subassembly  114   c  of intermediate conveyor assembly  133   c . If the read information is not associated with a sample on which assay instrument  108   c  is scheduled to perform an assay, the controller of host conveyor assembly  102  adjusts the control signal transmitted to diverter  142   c , which diverts the respective carrier  101  to a portion  145   c  of host conveyor assembly  102  that bypasses intermediate conveyor assembly  133   c  and assay instrument  108   c . Host conveyor then continues to transport the bypassed carriers  101  toward diverter  124  and the next assay instrument  108   a.    
     Host conveyor assembly  102  can continue to divert carriers  101  from host conveyor assembly  102  to input portion  146   c  of buffer conveyor subassembly  114   c  of intermediate conveyor assembly  133   c  until input portion  146   c  of buffer conveyor subassembly  114   c  is full. At that point, the controller of host conveyor assembly  102  will continue to divert carriers  101  to downstream portion  145   c  of host conveyor assembly  102  regardless of whether the sample contained within receptacle  103  coupled to the carrier  101  is scheduled for an assay to be performed by assay instrument  108   c , until space is available on input portion  146   c  of buffer conveyor subassembly  114   c  to accept additional carriers  101 . 
     Once a carrier  101  is diverted from host conveyor assembly  102  to input portion  146   a  of buffer conveyor subassembly  114   a , the controller of host conveyor assembly  102  provides a notification to controller  200   a  of intermediate conveyor assembly  133   a  that a carrier  101  was diverted. And in some embodiments, the controller of host conveyor assembly  102  transmits information about the diverted carrier  101 , for example, an identifier of the carrier  101 , receptacle  103 , or both, to controller  200   a.    
     Once a predetermined minimum number of carriers  101  have been queued on input portion  146   c , controller  200   c  can notify the controller of assay instrument  108   c  that the predetermined minimum number of carriers  101  and, thus, samples in processing receptacles  103  are available for processing by assay instrument  108   c . In some embodiments, the predetermined minimum number of carriers  101  is at least five carriers  101 . In other embodiments, the predetermined minimum number of carriers  101  is less than five. In some embodiments, the predetermined minimum number of carriers  101  equals the number of cavities defined by a signal assay receptacle  160   c . For example, if a single assay receptacle  160   c  defines five cavities for receiving five samples, the predetermined minimum number of carriers equals five. 
     Input portion  146   c  transports diverted carriers  101  towards position  147   c  on buffer conveyor subassembly  114   c  and queues a plurality of carriers  101  until assay instrument  108   c  is ready to start processing samples contained in receptacles  103  coupled to carriers  101 . In some embodiments, as a carrier  101  on buffer conveyor subassembly  114   c  passes sensor  148   c , sensor  148   c  reads information from the passing carrier  101 , receptacle  103 , or both, and transmits a signal to controller  200   c  of intermediate conveyor assembly  133   c  that includes the read information. Controller  200   c  of intermediate conveyor assembly  133   c  can then determine whether the read information, for example, an identifier, is associated with or matches the information transmitted from the controller of host conveyor assembly  102  to intermediate conveyor assembly  133   c  about the respective diverted carrier  101 . If the read information matches or is associated with the transmitted information, controller  200   c  of intermediate conveyor assembly  133   c  sends a control signal to diverter  150   c , which diverts the respective carrier  101  from input portion  146   c  of buffer conveyor subassembly  114   c  to spur conveyor subassembly  116   c . If the read information does not match or is not associated with the transmitted information, controller  200   c  of intermediate conveyor assembly  133   c  adjusts the control signal to diverter  150   c , which divert the carrier  101  from input portion  146   c  of buffer conveyor subassembly  114   c  directly to output portion  162   c  of buffer conveyor subassembly  114   c , bypassing spur conveyor subassembly  116   c.    
     After being transferred to spur conveyor subassembly  116   c  of intermediate conveyor assembly  133   b , spur conveyor subassembly  116   c  transports the carrier  101  to processing position  154   c  within assay instrument  108   c . For example, gripper  188  clamps the carrier  101  at position  153   c , and moves towards processing position  154   c  until the carrier  101  is at position  154   c . Sensor  156   c  can then read information from the carrier  101 , receptacle  103  coupled thereto, or both, when carrier  101  is at processing position  154   c . Sensor  156   c  can also transmit a signal to controller  200   c  of intermediate conveyor assembly  133  that includes the read information. Controller  200   c  of intermediate conveyor assembly  133   c  can then determine whether the read information, for example, an identifier, is associated with a sample on which assay instrument  108   c  is scheduled to perform an assay. This determination can be based on information stored in the laboratory information system  223 . In some embodiments, another sensor of spur conveyor subassembly detects whether carrier  101  is indeed at position  154   c . If the read information is associated with a sample on which assay instrument  108   c  is scheduled to perform an assay, controller  200   c  then sends a notification to the communication interface of the controller of assay instrument  108  that processing of the sample within the processing receptacle  103  coupled to carrier  101  located at processing position  154  can begin. As explained above, pipettor  158   c  of assay instrument  108   c  can aspirate at least a portion of a sample from receptacle  103  coupled to carrier  101  at processing position  154   c , and pipettor  158   c  can subsequently dispense the portion of the aspirated sample into a cavity defined by assay receptacle  160   c . After assay instrument  108   c  completes the processing of samples within processing receptacle  103  coupled to carrier  101  at processing position  154   c , the communication interface of the controller of assay instrument  108  sends a notification to controller  200   c  of intermediate conveyor assembly  133   c  that processing is complete, and spur conveyor spur conveyor subassembly  116   c  then transports the carrier  101  away from processing position  154   c  and back to position  153  on spur conveyor subassembly  116   c . Diverter  150   c  can then transport the carrier  101  to output portion  162   c  of buffer conveyor subassembly  114   c . In some embodiments, the total time it takes to (1) transport carrier  101  from position  153   c  to processing position  154   c  using spur conveyor subassembly  116   c , (2) process the sample contained with the sample receptacle  103  coupled to the carrier  101  at position  154   c  (i.e., aspirate at least a portion of a sample from receptacle  103  using automated pipettor  158   c  of assay instrument  108   a ), and (3) transport the carrier  101  from processing position  154  to position  153  using spur conveyor subassembly  116  takes less than or equal to about 1 minute. 
     If the information read by sensor  156  is not associated with a sample on which assay instrument  108   c  is scheduled to perform an assay, controller  200   c  notifies the communication interface of the controller of assay instrument  108  that processing should not begin, and spur conveyor subassembly  116   c  transports the carrier  101  back to position  153   c . Diverter  150   c  then transports the carrier to output portion  162   c  of buffer conveyor subassembly  114   c . The steps of transporting a carrier  101  from position  153   c  to processing position  154   c  using spur conveyor subassembly  116 , processing the sample contained with the sample receptacle  103  coupled to the carrier  101  at position  154   c , and transporting the carrier  101  from processing position  154   c  to position  153   c  using spur conveyor subassembly  116   c  is repeated as long as long as minimum number of carriers  101  are on the input portion  146   c  of buffer conveyor subassembly  114   c , the output portion  162   c  of buffer conveyor subassembly  114   c  is not full, and consumables, waste space, and reagents are available within assay instrument  108   c.    
     Output portion  162   c  of buffer conveyor subassembly  114   c  transports the carrier  101  received from spur conveyor subassembly  116   c  to position  167   c . When sensor  166   c  detects the presence of a carrier  101  at position  167   c , diverter  164   c  is actuated and transports the carrier  101  back to host conveyor assembly  102 . 
     Host conveyor assembly  102  continues to transport the carriers  101  either bypassed by assay instrument  108   c  or received from output portion  162   c  of buffer conveyor subassembly  114   a  toward the next assay instrument  108   a . As carriers  101  approach diverter  124 , sensor  128  detects the presence of a carrier  101  within a recess defined by diverter  124 , and the controller of host conveyor assembly  102  in communication with sensor  128  actuates diverter  124 , which transfers the carrier to first portion  118  of host conveyor assembly  102 . First portion  118  of host conveyor assembly  102  continues to transport carriers  101  toward assay instrument  108   a.    
       FIG. 16  illustrates an exemplary embodiment of processing carriers  101  and sample receptacles  103  using host conveyor assembly  102  and any one pairing of intermediate conveyor assemblies  133   a ,  133   b , and  133   c , and assay instruments  108   a ,  108   b , and  108   c . At step  302 , intermediate conveyor assembly  133  awaits a carrier  101  and processing receptacle  103  coupled to the carrier  101  from host conveyor assembly  102 . For example, intermediate conveyor assembly  133  waits for diverter  142  to transport a carrier  101  from host conveyor assembly  102  to input portion  146  of buffer conveyor subassembly  114 . 
     At step  304 , information read from carrier  101 , receptacle  103 , or both, on host conveyor assembly  102  is compared with information stored in laboratory information system  223  to determine whether a sample contained within the processing receptacle  103  is scheduled for an assay to be performed by the respective assay instrument  108 . If it is verified that an assay is to be performed by the respective assay instrument  108  on the sample contained within processing receptacle  103 , diverter  142  transports the respective carrier  101  and receptacle  103  to input portion  146  of buffer subassembly  114 . At step  306 , system  100  determines whether there is a predetermined minimum number of carriers  101  and receptacles  103  on input portion  146  of buffer conveyor subassembly  114  to begin processing with assay instrument  108 . If a predetermined minimum number of carriers  101  and receptacles  103  are not present on input portion  146  of buffer conveyor subassembly  114 , steps  302  and steps  304  are repeated. Once a predetermined minimum number of carriers  101  and receptacles  103  are present on input portion  146  of buffer conveyor subassembly  114 , system  100  continues to step  308 . 
     At step  308 , information about the samples contained in receptacles  103  coupled to carriers on input portion  146  of buffer conveyor subassembly  114  is transmitted to assay instrument  108 . This information can be information read from carriers  101  or receptacles  103  from any of the sensors within system  100 , or the information can include specific identification of what assays to perform on which samples in receptacles  103  on input portion  146  of buffer conveyor assembly  114 . 
     Next, at step  310 , carriers  101  are transported one at a time to processing position  154  of assay instrument  108 . For example, input portion  146  transports a carrier to position  147 , diverter  150  transports carrier  101  to position  153 , and gripper  188  of spur conveyor subassembly  116  transports carrier  101  to processing position  154 . 
     At step  312 , intermediate conveyor assembly verifies that the sample contained in receptacle  103  coupled to the carrier  101  at processing position  154  of assay instrument  108  is scheduled for an assay to be performed by the respective assay instrument  108 . For example, information read by sensor  156   a  from carrier  101 , receptacle  103 , or both, when carrier  101  is at processing position  154  of assay instrument  108  is compared with information stored in laboratory information system  223  or with information received from host conveyor assembly  102  about the respective carrier  101  and receptacle  103 . If the sample in receptacle  103  coupled to the carrier  101  at processing position  154  of assay instrument  108  is scheduled for an assay to be performed by the respective assay instrument  108 , system  100  continues to step  314 . 
     At step  314 , assay instrument  108  processes the sample contained within receptacle  103  coupled to carrier  101  at processing position  154 . For example, assay instrument  108  can aspirate a portion of the sample contained within receptacle  103  using automated pipettor  158  of assay instrument  108 , and can dispense the aspirated portion of the sample into a cavity defined by an assay receptacle  160 . In some embodiments, assay instrument  108  aspirates a plurality of portions of the sample contained within receptacle  103  using automated pipettor  158  of assay instrument  108 , and dispenses the plurality of aspirated portions of the sample into either a plurality of cavities defined by a single assay receptacle  160  (for example, an MTU) or a plurality of cavities defined by a plurality of assay receptacles  160 . Assay instrument  108  can then perform one or more assays on the sample portions dispensed into assay receptacle(s)  160 . 
     At step  316 , after interaction between assay instrument  108  and receptacle  103  coupled to the carrier  101  at processing position  154  of assay instrument  108 , carrier  101  and the respective receptacle  103  are transported back to host conveyor assembly  102 . For example, gripper  188  of spur conveyor subassembly  116  transports the carrier  101  from processing position  154  to position  153 , diverter  150  transports the carrier  101  from position  153  to position  163  on output portion  162  of buffer conveyor subassembly  114 , and output portion  162  transports the carrier  101  to a position adjacent diverter  164  at which diverter  164  transports the carrier  101  back to host conveyor assembly  102 . 
     At step  318 , system  100  determines whether there are additional carriers  101  and respective receptacles  103  for processing on input portion  146  of buffer conveyor subassembly  114 . If so, steps  310 - 316  are repeated. If not, intermediate conveyor assembly  133  returns to step  306  and waits for a predetermined number of receptacles to be queued on input portion  146  of buffer conveyor subassembly  116 . 
     3. Hardware and Software 
     Aspects of this disclosure are implemented via control and computing hardware components, user-created software, data input components, and data output components. Hardware components include computing and control modules (e.g., system controller(s)), such as microprocessors and computers, configured to effect computational and/or control steps by receiving one or more input values, executing one or more algorithms stored on non-transitory machine-readable media (e.g., software) that provide instruction for manipulating or otherwise acting on the input values, and output one or more output values. Such outputs may be displayed or otherwise indicated to an operator for providing information to the operator, for example information as to the status of the instrument or a process being performed thereby, or such outputs may comprise inputs to other processes and/or control algorithms. Data input components comprise elements by which data is input for use by the control and computing hardware components. Such data inputs may comprise position sensors, motor encoders, as well as manual input elements, such as graphic user interfaces, keyboards, touch screens, microphones, switches, manually-operated scanners, voice-activated input, etc. Data output components may comprise hard drives or other storage media, graphic user interfaces, monitors, printers, indicator lights, or audible signal elements (e.g., buzzer, horn, bell, etc.). 
     Software comprises instructions stored on non-transitory computer-readable media which, when executed by the control and computing hardware, cause the control and computing hardware to perform one or more automated or semi-automated processes. 
     While the present disclosure has been described and shown in considerable detail with reference to certain illustrative embodiments, including various combinations and sub-combinations of features, those skilled in the art will readily appreciate other embodiments and variations and modifications thereof as encompassed within the scope of the present disclosure. Moreover, the descriptions of such embodiments, combinations, and sub-combinations is not intended to convey that the disclosure requires features or combinations of features other than those expressly recited in the claims. Accordingly, the present disclosure is deemed to include all modifications and variations encompassed within the spirit and scope of the following appended claims. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way. 
     Embodiments have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. 
     The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, and without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. 
     The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. 
     While the invention has been described in connection with the above described embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
     All documents referred to herein are hereby incorporated by reference herein. No document, however, is admitted to be prior art to the claimed subject matter. 
     Furthermore, those of the appended claims which do not include language in the “means for performing a specified function” format permitted under 35 U.S.C. § 112, ¶6, are not intended to be interpreted under 35 U.S.C. § 112, ¶6, as being limited to the structure, material, or acts described in the present specification and their equivalents.