Abstract:
This disclosure provides systems, apparatuses, and methods for liquid transfer and performing reactions. In one aspect, a system includes a liquid transfer device having a housing having a pipette tip and a plunger assembly; and a reaction chamber, wherein the housing of the liquid transfer device is configured to sealably engage with the reaction chamber. In another aspect, a liquid transfer device including a housing having a pipette tip; and a plunger assembly disposed within the housing and the pipette tip, wherein a portion of the plunger assembly is configured to engage a fluid reservoir such that the plunger assembly remains stationary relative to the fluid reservoir and the housing moves relative to the plunger assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation and claims priority to U.S. patent application Ser. No. 13/242,999, filed Sep. 23, 2011, the entire contents of which are incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to systems and apparatuses for liquid transfer and carrying out reactions. 
       BACKGROUND 
       [0003]    Many diagnostic tests that involve biological reactions are required to be performed in laboratories by skilled technicians and/or complex equipment. Such laboratories may be the subject of government regulation. The costs of compliance with such regulations can increase the costs of diagnostic tests to patients and health care payers and exclude such tests from point-of-care facilities. There is a need for systems for performing diagnostic tests involving biological reactions that can be used without extensive training at the point of care. 
       SUMMARY 
       [0004]    The present disclosure provides systems, apparatuses and methods for transfer of liquids and processing of reactions, e.g., in diagnostic tests. 
         [0005]    In one aspect, the disclosure features a system that includes a liquid transfer device that includes a housing having a pipette tip and a plunger assembly; and a reaction chamber, wherein the housing of the liquid transfer device is configured to sealably engage with the reaction chamber. In some embodiments, the housing of the liquid transfer device can include a seal component configured to sealably engage with the reaction chamber. In some embodiments, the reaction chamber can include a seal component configured to sealably engage with the liquid transfer device. The systems can further include a fluid reservoir, and the reaction chamber can optionally be configured to lockably engage with the fluid reservoir. 
         [0006]    The liquid transfer device can be configured to lockably engage with the reaction chamber, e.g., without dispensing, prior to dispensing, and/or after dispensing a liquid sample. 
         [0007]    In some embodiments, the reaction chamber includes one or more components of a biological reaction. 
         [0008]    In another aspect, the disclosure features a liquid transfer device that includes a housing having a pipette tip; and a plunger assembly disposed within the housing and the pipette tip, wherein a portion of the plunger assembly is configured to engage a fluid reservoir such that the plunger assembly remains stationary relative to the fluid reservoir and the housing moves relative to the plunger assembly. 
         [0009]    In some embodiments, movement of the housing relative to the plunger assembly results in creation of a vacuum within the pipette tip and, optionally, the plunger assembly can be configured to lock in a position resulting in creation of the vacuum. The housing can be configured to move relative to the plunger assembly by pushing the housing down on the fluid reservoir. The device can further be configured to provide an auditory and/or visual indication that the plunger assembly is in a position resulting in the creation of the vacuum. 
         [0010]    A system can include the liquid transfer device and one or more of a fluid reservoir and reaction chamber. When a reaction chamber is included, the reaction chamber can be configured to unlock the plunger assembly when the liquid transfer device and the reaction chamber are interfaced. 
         [0011]    In another aspect, the disclosure features a liquid transfer device configured to draw a sample from a fluid reservoir by pushing the device against the reservoir and systems that include the liquid transfer device and one or both of a reaction chamber and fluid reservoir. 
         [0012]    In the systems described above, two or all three of the liquid transfer device, reaction chamber, and fluid reservoir can have compatible asymmetric cross-sections. 
         [0013]    In another aspect, the disclosure features methods that include (i) obtaining a liquid sample from a sample reservoir using a liquid transfer device described above; and (ii) dispensing the liquid sample, e.g., into a reaction chamber comprising one or more components of a reaction. 
         [0014]    In another aspect, the disclosure features methods that include (i) obtaining a liquid sample from a fluid reservoir using a liquid transfer device (e.g., a liquid transfer device described above); and (ii) dispensing the liquid sample into a reaction chamber, wherein the liquid transfer device sealably engages with the reaction chamber during or prior to dispensing. 
         [0015]    In another aspect, the disclosure features methods that include (i) obtaining a liquid sample from a fluid reservoir using a liquid transfer device (e.g., a liquid transfer device described above); and (ii) dispensing the liquid sample into a reaction chamber, wherein the liquid transfer device lockably engages with the reaction chamber during or prior to dispensing. The methods can further include (iii) interfacing the reaction chamber and the fluid reservoir, such that the reaction chamber lockably engages with the fluid reservoir. 
         [0016]    The systems, apparatuses, and methods disclosed herein can provide for simple analysis of unprocessed biological specimens. They can be used with minimal scientific and technical knowledge, and any knowledge required may be obtained through simple instruction. They can be used with minimal and limited experience. The systems and apparatuses allow for prepackaging or premeasuring of reagents, such that no special handling, precautions, or storage conditions are required. The operational steps can be either automatically executed or easily controlled, e.g., through the use of auditory and/or visual indicators of operation of the systems and apparatuses. 
         [0017]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0018]      FIG. 1  is an exploded view of an exemplary system as described herein. 
           [0019]      FIGS. 2A-2C  are exploded views of system subassemblies. 
           [0020]      FIG. 2D  is a view of the system mated and joined. 
           [0021]      FIGS. 3A-3D  depict the system in use. 
           [0022]      FIG. 4  depicts the system in the context of an exemplary detection device. 
           [0023]      FIGS. 5A-5C  depict the system in cross-section during sample collection. 
           [0024]      FIGS. 6A-6D  depict the system in cross-section during sample dispensing. 
           [0025]      FIGS. 7A-7B  depict single ( 7 A) and double ( 7 B) variants of the system. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    This application describes systems, apparatuses, and methods for transfer of liquids and processing of biological reactions (e.g., nucleic acid amplification reactions). 
         [0027]    Referring to  FIG. 1 , the system can include three subassemblies: a transfer device  100 , amplification chamber  200 , and an elution container  300 . Each subassembly can have a D-shaped or otherwise asymmetrical cross section  105 ,  205 ,  305  that is compatible with the other two subassemblies, such that the subassemblies may only be mated to each other in one orientation. 
         [0028]      FIGS. 2A-2C , show exploded views of the subassemblies  100 ,  200 , and  300 , respectively. In  FIG. 2A , the transfer device  100  includes a body  110  having a D-shaped or otherwise asymmetrical cross section  105  and a pipette tip  120 . The transfer device also includes a plunger unit  130  having a syringe plunger  135  that seals within the pipette tip  120  using an o-ring  140 . The plunger unit also includes flexible arms  131  having tabs  138  that are aligned with two sets of lower  112  and upper  113  slots in the body  110 . Ridges within the body  110  align with grooves in the plunger unit  130  to guide the plunger unit  130  up and down within the body  110 . When the plunger unit  130  is in the lower position, the tabs  138  insert into the lower slots  112 . When the plunger unit  130  is in the upper position, the tabs  138  insert into the upper slots  113 . A spring  150  fits over a spring guide  139  of the plunger unit  130 , and can be compressed against the cap  160  when the transfer device  100  is assembled. When the plunger unit  130  is in the upper position, an indicator  137  at the top of the spring guide  139  is visible through an indicator window  165  in the cap  160 . 
         [0029]    In  FIG. 2B , the amplification chamber  200  includes a body  210  having a D-shaped or otherwise asymmetrical cross-section  205  that is compatible with the cross-section  105  of the transfer device  100 . The amplification chamber body  210  also includes two tabs  215  that insert into either the lower slots  112  or upper slots  113  of the transfer device  100  when the two subassemblies are mated. The reaction chamber  200  also includes a microtube  220  having a retaining ring  225  that holds the microtube  220  within an aperture in the bottom of the amplification chamber body  210 . The microtube  220  can also have a seal  228  that covers the mouth  223  of the tube  220 . In some embodiments, the microtube  220  is optically permeable to allow monitoring of its contents. The amplification chamber  200  also includes a sealing component  230  that fits within the amplification chamber body  210  and over the microtube  220 , holding it in place. The sealing component  230  includes a pliant gasket  235  configured to seal against the pipette housing  180  when the two subassemblies are mated (see  FIGS. 6A-6D ). Two side tabs  240  are present near the bottom of the body  210  of the amplification chamber  200 . 
         [0030]    In  FIG. 2C , the elution container  300  has a D-shaped or otherwise asymmetrical cross-section  305  that is compatible with the cross-section  105  of the transfer device  100 . The elution container  300  includes an elution buffer reservoir  310  and a guide ring  320  compatible with a pipette housing  180  of the transfer device  100 . A seal can cover the mouth of the buffer reservoir  310  or guide ring  320 . Two notches  340  are present on the side walls  350  of the elution chamber  300 , into which insert the side tabs  240  of the amplification chamber  200  when the two subassemblies are mated. 
         [0031]      FIG. 2D  shows the three subassemblies of the system mated and joined for disposal. The transfer device  100  locks into the amplification chamber  200  by insertion of the amplification chamber tabs  215  into the upper slots  113  of the transfer device  100 . Similarly, the amplification chamber  200  locks into the elution chamber  300  by insertion of the side tabs  240  of the amplification chamber  200  into the notches  340  of the elution chamber  300 . In this configuration, the patient sample and any amplified nucleic acids are sealed within the system to prevent contamination. Approximate dimensions of the joined system are shown. 
         [0032]      FIGS. 3A-3D  show an overview of the system in operation. In  FIG. 3A , the transfer device  100  is positioned above the elution chamber  300  with their D-shaped cross-sections  105  and  305  aligned. In  FIG. 3B , the transfer device  100  is pushed down on the elution chamber  300 , such that the pipette tip  120  enters the buffer reservoir  310  and the plunger unit  130  remains stationary relative to the body  110  due to contact with a guide ring on the buffer reservoir  310 . This results in the plunger unit  130  in the upper position, compressing the spring  150  such that the indicator  137  shows through the indicator window  165 . The presence of the indicator  137  in the indicator window  165  and an audible click as the tabs  138  insert into the upper slots  113  provide auditory and visual feedback that the transfer device has been manipulated properly such that the pipette tip  120  is able to withdraw a portion of the sample from the buffer reservoir  310 . In  FIG. 3C , the transfer device  100  has been removed from the elution chamber  300  and positioned above the amplification chamber  200  with their D-shaped cross-sections  105  and  205  aligned. In  FIG. 3D , the transfer device  100  is pushed onto the amplification chamber  200 . The two tabs  215  of the amplification chamber  200  insert into the upper slots  113  of the transfer device  100 , displacing the tabs  138  and allowing the compressed spring  150  to relax and the plunger unit  130  to return to the lower position. The indicator  137  is no longer visible in the indicator window  165 , signaling that the contents of the pipette tip  120  have been emptied into the microtube  220 . The transfer device  100  is locked into the amplification chamber  200  by insertion of the amplification chamber tabs  215  into the upper slots  113  of the transfer device  100 . 
         [0033]      FIG. 4  shows the system with an exemplary detection device  400 . The detection device  400  includes a first station  410  adapted to securely hold the elution chamber  300  and a second station  420  adapted to securely hold the amplification chamber  200 . When in use, the transfer device  100  is moved between the elution chamber  300  at the first station  410  and the amplification chamber  200  at the second station  420 . The detection device includes a lid  430  that can be closed when the detection device  400  is in operation or for storage. A touchscreen user interface  440  is present for inputting data and displaying information regarding the assay. The second station  420  can include a bar code reader or similar device to automatically detect a bar code or similar code present on the amplification chamber  200 . The first  410  and second  420  stations can be adapted to heat or cool the contents of the elution chamber  300  and reaction chamber  200 . The second station  420  can also be adapted to provide optical, fluorescence, or other monitoring and/or agitation of the microtube  220 . 
         [0034]      FIGS. 5A-5C  show the system in cross-section during sample collection. In  FIG. 5A , the transfer device  100  is placed above the elution chamber  300  such that their cross sections  105 ,  305  are aligned. The plunger unit  130  is in the lower position and the tabs  138  are in the lower slots  112 . In  FIG. 5B , the transfer device  100  is lowered until one or more flanges  139  on the lower surface of the plunger unit  130  contact the guide ring  320 , and the pipette tip  120  and plunger tip  132  are inserted into the liquid sample  360 . The liquid sample  360  can be a patient or other sample or include a patient or other sample dissolved or suspended in a buffer. In  FIG. 5C , the transfer device  100  is pushed down by the user into the elution chamber  300 . The plunger unit  130  remains stationary through the contact of the one or more flanges  139  against the guide ring  320 , while the transfer device body  110  is lowered relative to the plunger unit  130  and elution chamber  300 . Simultaneously, a guide channel  116  in the transfer device is pushed downward relative to the guide ring  320 . The downward motion of the transfer device body  110  causes the pipette tip  120  to move downward relative to the plunger tip  132  and draw a liquid sample portion  365  into the pipette tip  120 . The downward motion of the transfer device body  110  relative to the plunger unit  130  also compresses the spring  150 , moves the tabs  138  from the lower slots  112  to the upper slots  113 , and causes the indicator  137  to be visible through the indicator window  165 . The transfer device  100  with the liquid sample portion  365  can now be lifted off of the elution chamber  300  and is ready for transfer and dispensing. 
         [0035]      FIGS. 6A-6D  show the system in cross-section during sample dispensing. In  FIG. 6A , the transfer device  100  is placed above the amplification chamber  200  such that their cross sections  105 ,  205  are aligned. The amplification chamber  200  is held within the second station  420  of the detection device  400  with the microtube  220  seated within a tube holder  428 . In  FIG. 6B , the transfer device  100  is lowered until two inner tabs  250  within the amplification chamber  200  engage two ridges  170  in the lower sides of the transfer device body  110 , the tabs  215  insert into the lower slots  112  of the transfer device  100 , and the gasket  235  engages the pipette housing  180 . This prevents the transfer device  100  from being easily removed from the amplification chamber  200  once dispensing has been started and prevents release of the sample. In  FIG. 6C , the transfer device  100  is further lowered onto the amplification chamber  200 , such that the amplification chamber tabs  215  insert into the upper slots  113  of the transfer device and displace the plunger unit tabs  138 . Simultaneously, the pipette tip  120  pierces the seal  228  on the microtube  220 . In  FIG. 6D , the plunger unit  130 , no longer held in the upper position, moves to the lower position as the spring  150  expands. This causes the plunger tip  132  to move downward within the pipette tip  120  and dispense the liquid sample portion  365  into the microtube  220 . The liquid sample portion  365  rehydrates a dried reagent pellet  280  in the microtube  220 , initiating reaction (e.g., an amplification reaction). The transfer device  100  is locked in place on the amplification chamber  200  by the tabs  215  inserted into the upper slots  113 , and any product of the amplification reaction is sealed within the unit by the gasket  235 . 
         [0036]      FIGS. 7A and 7B  are three-quarter cross sections showing the system configured for one or two microtubes  220 .  FIG. 7A  shows the transfer device  100  and amplification chamber  200  as described above with one pipette tip  120  and one microtube  220 .  FIG. 7B  shows the transfer device  100  and amplification chamber  200  with two pipette tips  120  and two microtubes  220 . Using the device in  FIG. 7B , parallel reactions (e.g., amplification reactions) can be performed on two portions of one sample. 
         [0037]    The systems and apparatuses disclosed herein can be used to perform reactions, e.g., utilizing biological components. In some embodiments, the reactions involve production of nucleic acids, such as in nucleic acid amplification reactions. Exemplary nucleic acid amplification reactions suitable for use with the disclosed apparatuses and systems include isothermal nucleic acid amplification reactions, e.g., strand displacement amplification, nicking and extension amplification reaction (NEAR) (see, e.g., US 2009/0081670), and recombinase polymerase amplification (RPA) (see, e.g., U.S. Pat. No. 7,270,981; U.S. Pat. No. 7,666,598). In some embodiments, a microtube can contain one or more reagents or biological components, e.g., in dried form (see, e.g., WO 2010/141940), for carrying out a reaction. 
         [0038]    The systems and apparatuses disclosed herein can be used to process various samples in reactions, e.g., utilizing biological components. In some embodiments, the samples can include biological samples, patient samples, veterinary samples, or environmental samples. The reaction can be used to detect or monitor the existence or quantity of a specific target in the sample. In some embodiments, a portion of the sample is transferred using a transfer device as disclosed herein. 
         [0039]    In some embodiments, a liquid transfer device or pipette tip disclosed herein can be configured to collect and dispense a volume between 1 μl and 5 ml (e.g., between any two of 1 μl, 2 μl, 5 μl, 10 μl, 20 μl, 50 μl, 100 μl, 200 μl, 500 μl, 1 ml, 2 ml, and 5 ml). 
         [0040]    The disclosure also features articles of manufacture (e.g., kits) that include one or more systems or apparatuses disclosed herein and one or more reagents for carrying out a reaction (e.g., a nucleic acid amplification reaction). 
         [0041]    A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, a transfer device as described herein can include three or more pipette tips. Accordingly, other embodiments are within the scope of the following claims.