Abstract:
A reaction receptacle apparatus includes one or more individual receptacles for containing chemical or biological substances. The one or more receptacles are arranged to be engaged by tubular elements of a substance transfer device for transferring substances into or out of the individual receptacles. Multiple receptacles are coupled to one another by a connecting rib structure that defines straight shoulders along opposite sides of the reaction receptacle apparatus, and the shoulders support the apparatus within reaction receptacle apparatus carrying structures. A contact-limiting element holding structure for holding contact-limiting elements, such as protective tips for tubular elements, is associated with each individual receptacle and holds a contact-limiting element in an operative orientation so as to be, operatively engageable by the tubular element of the substance transfer device. A receptacle apparatus manipulating structure permits the reaction receptacle apparatus to be moved from one location to another by a robotic manipulating device, and an information panel presents a surface on which human and/or machine readable information may be placed.

Description:
[0001]    This application claims the benefit of prior filed provisional application No. 60/046,800, filed May 2, 1997.  
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to reaction receptacles useful for containing chemical or biological substances.  
         BACKGROUND OF THE INVENTION  
         [0003]    Reaction receptacles or test tubes are commonly used in the chemical and biological arts to perform a variety of types of assays in a contained space. Assays that commonly have one or more steps performed in reaction receptacles include chemical reactions, immunoassays, and nucleic acid-based assays. Examples of such reactions and assays are thoroughly described in the available literature and are well known to those skilled in the art. While reaction receptacles are generally manufactured and sold as individual units or test tubes, it is common for practitioners to use holding racks to conveniently and collectively organize a group of reaction receptacles for performing multiple assays simultaneously or sequentially. In some instances, multiple reaction receptacles are assembled as a unitary piece.  
           [0004]    With most assays, a substance transfer device is used to dispense solutions into or remove solutions from reaction receptacles. The most familiar substance transfer devices are pipettes and aspirators including one or more tubular elements through which fluids are dispensed or withdrawn. When substance transfer devices are used in conducting a group of independent assays at about the same time or in close proximity to one another, there is always the concern that a substance transfer device will inadvertently serve as a vehicle in transferring substances or contaminants between reaction receptacles. An additional concern is that the practitioner will improperly add substances into or remove substances from a reaction receptacle. To minimize the risk of cross-contamination and pipetting and aspirating errors, practitioners must carefully monitor substance transfers and exercise nearly flawless precision when pipetting substances into or aspirating substances from reaction receptacles. Avoiding cross-contamination and pipetting and aspirating mistakes is particularly important when the assay is diagnostic in nature or is designed to provide information concerning the progress of a patient&#39;s disease over time or the success of a treatment regimen.  
           [0005]    One way to limit opportunities for cross-contamination is to reduce the amount of surface area on the substance transfer device that can come into contact with the contents of a reaction receptacle. This objective can be achieved by using a contact-limiting element, such as a pipette tip, which essentially serves as a barrier between the outer surface of the pipette and the contents of a reaction receptacle. And by selecting a pipette tip of sufficient length and volume, contact between the pipette and contents of a reaction receptacle can be substantially eliminated. This is because substances from the reaction receptacle will be drawn into a portion of the pipette tip which falls below the bottom surface of the pipette. Of course, in most instances, it will also be important to have a single pipette tip dedicated to each reaction receptacle.  
           [0006]    Where a number of pipette tips are used to perform multiple assays simultaneously or sequentially, practitioners typically need to position a supply of pipette tips at a location that can be conveniently accessed by at least one pipette. Providing a sufficient quantity of pipette tips becomes more complicated when the substance transfer device functions robotically in an automated (or partially automated) assay instrument. In an automated format, a large reserve of pipette tips may need to be placed in the instrument at a site that is accessible by the pipette, but which limits the total amount of space required. Accordingly, there is a need for pipette tips that are readily accessible by a robotic pipette without requiring the pipette to engage in complicated movements or to travel over substantial distances.  
           [0007]    Another problem presented by conventional reaction receptacles is that they come packaged as individual test tubes that are not amenable to manipulation by an automated assay instrument. Individual reaction receptacles hinder throughput efficiency since the practitioner and instrument must each handle the reaction receptacles separately. And because conventional reaction receptacles are not provided with any structure that permits them to be manipulated by an automated instrument, reaction receptacles are generally stationed at one situs within the instrument and are not afforded any automated mobility. This lack of movement imposes certain architectural limitations and assay inefficiencies since the instrument must be designed around the positioning of the reaction receptacles. Accordingly, there is a need for a reaction receptacle apparatus which can be manipulated by an automated assay instrument, where the apparatus may include one reaction receptacle or plurality of reaction receptacles coupled together as a single operative unit.  
         SUMMARY OF THE INVENTION  
         [0008]    It is an object of the present invention to provide a reaction receptacle apparatus that meets one or more of the needs set forth above. Thus, a reaction receptacle apparatus according to the present invention can be used to perform chemical or biological assays and comprises at least one reaction receptacle for containing substances used in performing such assays. When the reaction receptacle apparatus includes a plurality of reaction receptacles, the reaction receptacles are operatively coupled to one another, either directly or indirectly, and are capable of interacting with a substance transfer device that dispenses substances into or withdraws substances from some or all of the plurality of reaction receptacles making up the reaction receptacle apparatus.  
           [0009]    So that the substance transfer device can safely and efficiently dispense substances into or withdraw substances from the reaction receptacles, one embodiment of the present invention provides for one or more contact-limiting elements associated with the reaction receptacle apparatus. The contact-limiting elements of this embodiment are constructed and arranged to be operatively engaged by the substance transfer device to limit potentially contaminating contact between at least a portion of the substance transfer device and a potentially contaminating substance that is dispensed into or withdrawn from a reaction receptacle by the substance transfer device. One or more contact-limiting elements are associated with each of one or more of the reaction receptacles of the reaction receptacle apparatus.  
           [0010]    When the present invention includes contact-limiting elements, the reaction receptacle apparatus is outfitted with one or more contact-limiting element holding structures, each contact-limiting element holding structure being preferably associated with a different contact-limiting element. Each of the contact-limiting element holding structures is constructed and arranged to (i) receive and removably hold the associated contact-limiting element in an operative orientation in proximity to the associated receptacle so as to be operatively engageable by the substance transfer device, and (ii) allow the associated contact-limiting element to be removed from the associated contact-limiting element holding structure when the associated contact-limiting element is operatively engaged by the substance transfer device.  
           [0011]    Because this embodiment of the reaction receptacle apparatus is supplied with its own contact-limiting elements, an automated assay instrument can be constructed so that the substance transfer device avoids complex motions and conveniently engages the contact-limiting elements when the reaction receptacle apparatus is brought into an operative position within the instrument. An additional benefit of this embodiment is that the instrument does not have to be configured to receive a store of contact-limiting elements, and practitioners are spared having to monitor the volume of contact-limiting elements in an instrument while assays are being run.  
           [0012]    A further embodiment of the present invention is a reaction receptacle apparatus including receptacle apparatus manipulating structure to permit manipulation of the apparatus by an automated reaction receptacle manipulating device. According to this embodiment, the receptacle apparatus manipulating structure is constructed and arranged to be engaged by an automated reaction receptacle manipulating device, so that the reaction receptacle apparatus can be robotically manipulated within an automated instrument. The reaction receptacle apparatus of this embodiment includes at least one reaction receptacle and may optionally include the contact-limiting elements and associated contact-limiting element holding structures described above.  
           [0013]    Other features and characteristics of the present invention, as well as the methods of operation, functions of related elements of structure and the combination of parts, and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view of a first embodiment of a reaction receptacle apparatus and contact-limiting element in the form of a tiplet embodying aspects of the present invention;  
         [0015]    [0015]FIG. 2 is a side elevation of a contact-limiting tiplet;  
         [0016]    [0016]FIG. 3 is a partial bottom view of the reaction receptacle apparatus of FIG. 1 taken in the direction indicated by arrow “III” in FIG. 1;  
         [0017]    [0017]FIG. 4 is a side elevation of a first alternate embodiment of the reaction receptacle apparatus of the present invention;  
         [0018]    [0018]FIG. 5 is a top view of the reaction receptacle apparatus of FIG. 4;  
         [0019]    [0019]FIG. 6 is a cross-section in the direction “VI-VI” of FIG. 4;  
         [0020]    [0020]FIG. 7 is a cross-section in the direction “VII-VII” in FIG. 4;  
         [0021]    [0021]FIG. 8 is a cross-section in the direction “VIII-VIII” in FIG. 4;  
         [0022]    [0022]FIG. 9 is a perspective view of an exemplary reaction receptacle apparatus manipulating device for manipulating a reaction receptacle apparatus according to the present invention;  
         [0023]    [0023]FIG. 10 is a side elevation, partially in cross-section, of the manipulating device of FIG. 9 with a reaction receptacle apparatus resident therein;  
         [0024]    [0024]FIG. 11 is a side elevation, partially in cross-section, of an exemplary reaction receptacle apparatus processing device for processing a reaction receptacle apparatus according to the present invention;  
         [0025]    [0025]FIG. 12 is a partial side view of a reaction receptacle apparatus according to the present invention and a skewed wobbler plate for imparting an oscillatory vibration to the apparatus;  
         [0026]    [0026]FIG. 13 is a cross-section showing a reaction receptacle apparatus according to the present invention carried by a receptacle carrier structure within a receptacle apparatus processing device with a tubular element of the processing device engaging a contact-limiting tiplet disposed within a contact-limiting holding structure of the apparatus of the present invention;  
         [0027]    [0027]FIG. 14 is a cross-section showing the reaction receptacle apparatus disposed within the receptacle carrier structure with the tubular elements and the contact-limiting tiplet disposed on the end of the tubular element inserted into the apparatus;  
         [0028]    [0028]FIG. 15 is a perspective view of a second alternate embodiment of a reaction receptacle apparatus of the present invention;  
         [0029]    [0029]FIG. 16 is a perspective view of a third alternate embodiment of a reaction receptacle apparatus of the present invention; and  
         [0030]    [0030]FIG. 17 is a side elevation of an alternate embodiment of a contact-limiting tiplet engaged by a tubular element of a substance transfer device.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    As shown in FIGS. 1 and 3, a preferred embodiment of a reaction receptacle apparatus according to the present invention is designated generally by the reference character  160 . As shown, the reaction receptacle apparatus  160  preferably comprises a plurality of individual receptacles  162 . In the illustrated embodiment, the reaction receptacle apparatus  160  includes five individual receptacles  162 , but a reaction receptacle according to the present invention may include any number of receptacles  162 , as desired. Ten receptacles  162  are preferred and five receptacles  162  are most preferred. Each individual receptacle  162  preferably has a construction similar to that of a conventional test-tube, i.e., a cylindrical body with a circular open mouth  161  and a rounded closed bottom end  163 . Each individual receptacle can, however, have other shapes, such as rectangular, octagonal, etc., and may have an upper end equipped with a closable lid structure or the like. Where the reaction receptacle includes a plurality of receptacles, the receptacles may have the same or different shapes and sizes. The receptacles  162  are preferably oriented in an aligned arrangement comprising a single row of receptacles  162  and are connected to one another by a connecting rib structure  164  which defines a downwardly facing shoulder  165  extending longitudinally along either side of the reaction receptacle apparatus  160 . The receptacles  162  may be oriented in a different nonlinear arrangement, or a single reaction receptacle apparatus may comprise more than one row of receptacles  162 .  
         [0032]    Reaction receptacle apparatus  160  is preferably a single, integral piece formed of injection molded polypropylene. The most preferred polypropylene is sold by Montell Polyolefins, of Wilmington, Del., product number PD701NW. The Montell material is used because it is readily moldable and is chemically compatible with the preferred biological assays performed in the reaction receptacle apparatus. Moreover, the Montell material experiences a limited number of static discharge events, which is important when the results of the assay performed in the reaction receptacle apparatus are determined by the detection of light emitted by the contents of the apparatus at the conclusion of the assay. Static discharge events can interfere with accurate detection or quantification of the light output.  
         [0033]    An arcuate shield structure  185  provided at one end of the reaction receptacle apparatus  160  includes an upper portion  169  and a lower portion  173 . A receptacle apparatus manipulating structure  166 , adapted to be engaged by a reaction receptacle manipulating device, extends from the shield upper portion  169 . Receptacle apparatus manipulating structure  166  comprises a laterally extending plate  168  extending from shield upper portion  169  with a transverse piece  167  on the opposite end of the plate  168 . A gusset wall  183  extends downwardly from lateral plate  168  between shield lower portion  173  and transverse piece  167 .  
         [0034]    As shown in FIG. 3, the shield lower portion  173  and transverse piece  167  have mutually facing convex surfaces. The reaction receptacle apparatus  160  is preferably engaged by manipulating devices and other components, as will be described below, by moving an engaging member of the manipulating device laterally (in the direction “A”) into a space  50  between the shield lower portion  173  and the transverse piece  167 . The convex surfaces of the shield lower portion  173  and transverse piece  167  provide for wider points of entry for an engaging member undergoing a lateral relative motion into the space  50 . Vertically extending, raised arcuate ridges  171 ,  172  may be provided in the middle of the convex surfaces of the transverse piece  167  and shield lower portion  173 , respectively. The purpose of ridges  171 ,  172  will be described below.  
         [0035]    A label-receiving structure  174  provided on an end of the reaction receptacle apparatus  160  opposite receptacle apparatus manipulating structure  166  preferably includes an upper portion  71  and a lower portion  75 , which together present a flat label-receiving surface  175 . The label-receiving structure  174  further includes a vertical gusset wall  78  extending between upper portion  71  and the endmost receptacle  162  to provide a brace for the upper portion  71 . As best shown in FIG. 4, a gusset wall  80  of the label-receiving structure  174  is oriented vertically and extends diagonally from a location proximate rib structure  164  toward a lower end of lower portion  75  to provide a brace for lower portion  75 . Labels, such as machine-scannable bar codes, can be applied to the surface  175  to provide identifying and instructional information on the reaction receptacle apparatus  160 . Labels can be applied to surface  175  by any suitable means, such as, printing them onto surface  175  or adhering a label sheet, by means of an adhesive, to surface  175 .  
         [0036]    Substances can be dispensed into or removed from the receptacles  162  through their open mouths  161  by means of a substance transfer device, such as a pipetting or aspirating apparatus (hereinafter referred to collectively as “pipetting apparatus” or “pipette”). The pipetting apparatus may include a slender tubular element (see, e.g., tubular element  220  in FIG. 11) that is inserted into the receptacle  162  through the open mouth  161  and which may come into contact with the receptacle  162  itself, the substance contained in the receptacle  162 , and/or the substance being dispensed into the receptacle. A pipetting apparatus may be used to dispense substances into and/or remove substances from multiple individual receptacles  162 . Accordingly, to reduce the likelihood of cross-contamination between individual receptacles  162 , it is desirable to limit the amount of the pipetting apparatus that comes into contact with the substance or walls of any receptacle  162 . Therefore, a contact-limiting element, which may take the form of a protective disposable tip, or tiplet, covers the end of the tubular element of the pipetting apparatus. One contact-limiting element is used to cover the end of the tubular element while the pipetting apparatus engages one individual receptacle to dispense substance into or withdraw substance from the receptacle. Before the pipetting apparatus moves to the next receptacle, that contact-limiting element is discarded or stored for later use with that receptacle, and a new contact-limiting element is engaged by the tubular element.  
         [0037]    As shown in FIG. 2, a preferred embodiment of a contact-limiting element comprises a tiplet  170 . In the preferred embodiment, tiplet  170  comprises a tubular body  179  having a peripheral flange  177 , preferably extending radially with respect to said tubular body  179 , and a thickened wall portion  178 , adjacent the peripheral flange  177 , having a generally larger diameter than a remaining portion of the tubular body  179  of the tiplet  170 . An axially extending inner bore  180  passes through the tiplet  170 . Bore  180  includes an outwardly flared end  181 , which facilitates insertion of a bottom free end of a tubular element of a pipetting apparatus into the bore  180  of tiplet  170 . The inner diameter of inner bore  180  provides an interference fit with the outer diameter of the tubular element to frictionally secure tiplet  170  onto the tubular element when the bottom end of the tubular element is forced into the inner bore  180 .  
         [0038]    In the illustrated embodiment, the tubular body  179  and inner bore  180  are generally cylindrical in shape, consistent with the typically cylindrical shape of the tubular element of a substance transfer device, such as a pipetting or aspirating device. The present invention is not limited, however, to contact-limiting elements having tubular bodies and inner bores that are cylindrical, as the tubular body and inner bore of the contact-limiting element may have a shape that is other than cylindrical to conform to non-cylindrical tubular elements of substance transfer devices.  
         [0039]    The bottom end of the tiplet  170  preferably includes a beveled portion  182 . When tiplet  170  is used on the bottom of the tubular element of a pipetting apparatus used for aspirating substances from a receptacle  162 , the beveled portion  182  will prevent a vacuum from forming between the end of the tiplet  170  and the bottom  163  of the receptacle  162 .  
         [0040]    An alternate embodiment of a contact-limiting element is a tiplet designated by reference number  470  in FIG. 17. Tiplet  470  comprises a tubular body  479  having a peripheral flange  477 , preferably extending radially with respect to said tubular body  479 , and a thickened wall portion  478 , adjacent the peripheral flange  477 , of generally larger diameter than a remaining portion of the tubular body  479  of the tiplet  470 . An axially extending inner bore  480  passes through the tiplet  470 . Bore  480  includes a bevelled end  481 , which facilitates insertion of an upper end  483  of the tubular body  479  into a bottom free end of a tubular element  420 . The outer diameter of upper end  483  of the tubular body  479  provides an interference fit with the inner diameter of the tubular element  420  to frictionally secure tiplet  470  onto the tubular element  420  when the upper end  483  of the tubular body  479  is inserted into the bottom free end of the tubular element  420 .  
         [0041]    Again, the tubular body  479  and inner bore  480  need not necessarily be generally cylindrical in shape, as illustrated in FIG. 17, may have a shape that is other than cylindrical to conform to non-cylindrical tubular elements of substance transfer devices.  
         [0042]    The bottom end of the tiplet  470  preferably includes a beveled portion  482 . When tiplet  470  is used on the bottom of the tubular element of a pipetting apparatus used for aspirating substances from a receptacle  162 , the beveled portion  482  will prevent a vacuum from forming between the end of the tiplet  470  and the bottom  163  of the receptacle  162 .  
         [0043]    As shown in FIG. 1, the reaction receptacle apparatus  160  preferably includes contact-limiting element holding structures in the form of tiplet holding structures  176  adjacent the open mouth  161  of each respective receptacle  162 . Each tiplet holding structure  176  provides an elongated orifice  150 , preferably generally cylindrical in shape, within which is received a contact-limiting tiplet  170  ( 470 ). An annular end face  152  extends about the orifice  150 , and when the tiplet  170  ( 470 ) is inserted into a tiplet holding structure  176 , the peripheral flange  177  ( 477 ) contacts the end face  152  of tiplet holding structure  176  to limit the depth to which the tiplet  170  ( 470 ) can be inserted into the orifice  150 . The outside diameter of the thickened wall portion  178  ( 478 ) is slightly larger than inside diameter of the orifice  150 . Alternatively, and preferably, a plurality of small, raised ribs  154  (see FIG. 3) extend longitudinally along the inner wall of the orifice  150  at different circumferentially-spaced positions. The crests of the raised ribs  154  define an inner diameter that is slightly smaller than the outer diameter of the thickened wall portion  178  ( 478 ). Accordingly, the tiplet holding structure  176  provides a sliding interference fit between the thickened wall portion  178  ( 478 ) and the inner diameter of the orifice  150  or between the thickened wall portion  178  ( 478 ) and the crests of the ribs  154 . Thus, tiplet  170  ( 470 ) is held securely within the orifice  150  of the tiplet holding structure  176  so the tiplet  170  ( 470 ) is unlikely to dislodge from the tiplet holding structure  176 , even if the reaction receptacle apparatus  160  is inverted. On the other hand, if the tiplet  170  ( 470 ) is frictionally engaged by the tubular element of a pipetting apparatus while the tiplet  170  ( 470 ) is held in the tiplet holding structure  176 , the frictional hold between the tiplet  170  ( 470 ) and the tubular element is greater than the frictional hold between the tiplet  170  ( 470 ) and the tiplet holding structure  176 . Thus, the tiplet  170  ( 470 ) should remain secured on the end of the tubular element when the tubular element is withdrawn in an axial direction from the orifice  150  of the tiplet holding structure  176 .  
         [0044]    Throughout the remainder of this specification, reference will be made only to tiplet  170  (the embodiment shown in FIG. 2). Those skilled in the art, however, will appreciate that the following descriptions and illustrations can apply to tiplet  470  (the embodiment shown in FIG. 17) as well.  
         [0045]    An alternate tiplet holding structure  76  is shown in FIGS. 4 and 5. Reaction receptacle apparatus  60  includes a tiplet holding structure  76  that is different from the tiplet holding structure  176  of reaction receptacle apparatus  160  of FIG. 1. In all other respects, however, reaction receptacle apparatus  60  is identical to reaction receptacle apparatus  160 . Tiplet holding structure  76  includes a tiplet-receiving orifice  79  with an end face  77  surrounding orifice  79  and forming a partial annulus. A slot  78  extends longitudinally along a wall of the tiplet holding structure  76 . Slot  78  allows the tiplet holding structure  76  to expand when a tiplet  170  is inserted into the tiplet holding structure  76 , and the resiliency of the material of which the reaction receptacle apparatus  60  is formed provides a frictional fit between a tiplet  170  and the tiplet holding structure  76 .  
         [0046]    As shown in FIGS. 1, 4, and  5 , connecting rib structure  164  extends along both sides of the reaction receptacle apparatus  160  and defines downwardly facing shoulders  165  with outer edges  192  along each side of the reaction receptacle apparatus  160  ( 60 ). The reaction receptacle apparatus  160  ( 60 ) is operatively supported within a diagnostic instrument or the like by means of the shoulders  165  resting on parallel, horizontal flanges spaced apart from one another by a distance slightly greater than the width of the individual receptacle  162 , but less than the width of the rib structure  164  between edges  192 . Such flanges may be defined by a slot extending from an edge of a reaction receptacle apparatus supporting plate. In an automated instrument for processing the contents of a reaction receptacle apparatus, the reaction receptacle apparatus may be inserted into and removed from a supporting structure by a reaction receptacle apparatus manipulating device.  
         [0047]    At an end of the rib structure  164  opposite the receptacle apparatus manipulating structure  166 , two upwardly angled portions  82  provide upwardly angled shoulders  84  on both sides of the reaction receptacle apparatus  160  ( 60 ). The upwardly angled shoulders  84  facilitate sliding of the reaction receptacle apparatus  160  ( 60 ) onto a supporting structure.  
         [0048]    An exemplary device  20  for manipulating a reaction receptacle apparatus  160  ( 60 ) is shown in FIGS. 9 and 10. The device  20  includes a base structure  22  attached to a mounting bracket or mounting plate of an instrument which processes the contents of numerous reaction receptacle apparatuses according to the present invention and may perform one or more assays within each reaction receptacle apparatus  160 . The manipulating device  20  moves the reaction receptacle apparatuses from one location to another within the instrument.  
         [0049]    The manipulating device  20  further includes a rotating transport carrier  28  which rotates about a shaft  25  by means of a stepper motor  24  which turns a pulley  29  attached to the shaft  25  via a drive belt  27 . The shaft  25  and pulley  29  may be covered by a pulley housing  26 . The rotating transport carrier  28  includes a base plate  30  covered by a housing  32 . The housing  32  includes an opening  36  at one end thereof, and the base plate  30  includes a slot  31  formed therein. A manipulating hook  34  is mounted for sliding translation in the slot  31  and is attached to a threaded drive screw  40  that is actuated by a stepper motor  38  to extend and retract the manipulating hook  34  within the slot  31 .  
         [0050]    To engage the receptacle apparatus manipulating structure  166  of the reaction receptacle apparatus  160 , the manipulating hook  34  is extended to a forward position projecting from the opening  36  as shown in FIG. 9. A lateral translation of the manipulating hook  34  is effected, such as by effecting a small rotation of the rotating transport carrier  28 , to place the manipulating hook  34  in the space  50  between the lower portion  173  of the arcuate shield structure  185  and the transverse piece  167  of the receptacle apparatus manipulating structure  166 . With the manipulating structure  166  engaged, the stepper motor  38  retracts the drive screw  40 , pulling the manipulating hook  34  and the reaction receptacle apparatus  160  back into the rotating transport carrier  28 . The downwardly facing shoulders  165  defined by the connecting rib structure  164  of the reaction receptacle apparatus  160  are supported by the base plate  30  along opposite edges  42  of the slot  31 , thus supporting the reaction receptacle apparatus  160  in the rotating transport carrier  28 . With the reaction receptacle apparatus  160  secured within the rotating transport carrier  28 , the carrier  28  can be rotated by the stepper motor  24  to a different position at which the stepper motor  38  can extend the drive screw  40  and the manipulating hook  34  to push the reaction receptacle apparatus  160  out of the rotating transport carrier  28  and into a different location within the instrument.  
         [0051]    An exemplary reaction receptacle processing device  200  is shown in FIG. 11. Processing device  200  may represent one of many similar or related devices which together make up a reaction receptacle processing instrument.  
         [0052]    The processing device  200  includes a housing  201  with an opening  202  formed therein. A reaction receptacle apparatus  160  can be inserted into the processing device  200  through the opening  202  and removed through the opening  202  by a manipulating device such as the manipulating device  20  shown in FIGS. 9 and 10 and described above. Inside the housing  201  the reaction receptacle apparatus is supported by a receptacle carrier structure  206  having a base plate  204  (see also FIGS. 13 and 14) with a receptacle receiving slot (not shown) formed therein so that the reaction receptacle apparatus  160  can be supported by means of portions of the plate  204  along opposite edges of the slot supporting the connecting rib structure  164  of the reaction receptacle apparatus  160 .  
         [0053]    Processing device  200  may be a mixing device for mixing the contents of the reaction receptacle apparatus  160 ; the processing device  200  may be a dispensing device for simultaneously dispensing substance into each of the individual receptacles  162  of the reaction receptacle apparatus  160 ; or the processing device  200  may be a device for simultaneously aspirating substance from each of the receptacles  162  of the reaction receptacle apparatus  160 . Alternatively, the processing device  200  may perform any combination of two or more of the above functions.  
         [0054]    As a mixing device, the receptacle carrier structure  206  may be coupled to an orbital mixing assembly comprising a stepper motor  208 , a drive wheel  210  with an eccentric pin  212  extending therefrom, and an idler wheel  216  having an eccentric pin  218  and being coupled to the drive wheel  210  by means of a belt  214 . As the stepper motor  208  rotates the drive pulley  210  which in turn rotates the idler pulley  216 , the eccentric pins  212  and  218  engage the receptacle carrier structure  206  thus moving the receptacle carrier structure and the reaction receptacle apparatus  160  carried thereby in an orbital path of motion. Movement at a sufficiently high frequency can cause sufficient agitation of the reaction receptacle apparatus  160  to mix the contents thereof.  
         [0055]    As shown in FIGS. 1, 4, and  5 , lateral ribs  190  extend longitudinally along the outer walls of the receptacles  162  above the connecting rib structure  164  at diametrically opposed positions with respect to one another. The outer edges of the lateral ribs  190  are generally co-planar with the outer edges  192  of the connecting rib structure  164 . The lateral ribs provide additional strength and rigidity to the open mouth  161  of the receptacle  162 . In addition, the outer edges of the lateral ribs  190  can engage the sidewalls of a receptacle carrier structure  206 , as shown in FIGS. 13 and 14, to limit the extent to which the reaction receptacle apparatus  160  will be allowed to tilt laterally within the receptacle carrier structure  206 . Although it is generally preferred that lateral ribs  190  be provided on each of the receptacles  162 , lateral ribs  190 , when included, can be provided on less than all of the receptacles  162  as well.  
         [0056]    When presented in the receptacle carrier structure  206 , the reaction receptacle apparatus  160  can be engaged by a dispensing and/or aspirating system comprising an array of tubular elements  220 . The dispensing and/or aspirating system preferably includes five tubular elements  220  oriented so as to correspond to the orientations of the individual receptacles  162  of the reaction receptacle apparatus  160 . The tubular elements  220  are coupled to means for providing vertical movement of the free ends of the tubular elements  220  with respect to the reaction receptacle apparatus  160  to move the ends of the tubular elements  220  into and out of the individual receptacles  162  to aspirate and/or dispense substances. In addition, tubular elements  220  are coupled to means, such as a fluid pump and fluid source or a vacuum pump, for delivering fluid to each of the tubular elements  220  or providing a suction at each of the tubular elements  220 .  
         [0057]    As described above, however, before the tubular elements  220  are inserted into the reaction receptacles  162 , it is preferred that a contact-limiting tiplet  170  be placed on the end of each tubular element  220 . Accordingly, the tubular elements  220  are first lowered to simultaneously engage all of the tiplets  170  carried in their respective tiplet holding structures  176 . The array of tubular elements  220  can be coupled to means for providing lateral translation of the tubular elements  220  for moving the tubular elements  220  to a position above the tiplet holding structures  176 . Alternatively, the receptacle carrier structure  206  itself can be moved laterally to place the tiplet holding structures  176  below the respective tubular elements  220 . Where the receptacle carrier structure  206  is coupled to an orbital mixing assembly as described above, the stepper motor  208  can move the assembly a limited number of steps, thus moving the receptacle carrier structure  206  and the reaction receptacle apparatus  160  a portion of one orbital path to place the tiplet holding structures  176  below the tubular elements  220  as shown in FIG. 13.  
         [0058]    As shown in FIGS. 1, 4, and  5 , each of the respective tiplet holding structures  176  ( 76 ) is preferably disposed at a position between adjacent receptacles  162 . Locating the tiplet holding structures  176  ( 76 ) between the adjacent receptacles  162  places the tubular elements  220  on the orbital paths of the contact-limiting element holding structures  176  ( 76 ) as the reaction receptacle apparatus  160  is moved with respect to the pipettes  220 . Thus, the orbital mixer assembly can be used to properly position the tiplet holding structures  176  ( 76 ) with respect to the tubular elements  220 , as described above. In addition, placing the tiplet holding structures  176  ( 76 ) between adjacent receptacles  162  provides for a narrower profile of the reaction receptacle apparatus  160  ( 60 ) than if the tiplet holding structures  176  ( 76 ) were located on the outer portion of the receptacles  162  nearest the edge  192  of the connecting rib structure  164 .  
         [0059]    The processing device  200  may also include an array of fixed nozzles  222  for dispensing substances into the receptacles  162  of the reaction receptacle apparatus  160  held in the receptacle carrier structure  206 .  
         [0060]    As shown in FIG. 12, an alternate, oscillating mixing device  230  comprises a skewed wobbler plate  232  disposed on a shaft  234  driven by a motor (not shown). The reaction receptacle apparatus  160 , carried by a carrier structure (not shown), is moved with respect to the oscillating mixing device  230 —or the oscillating mixing  230  is moved with respect to the reaction receptacle apparatus  160 —until the wobbler plate  232  is disposed in the space  50  between the lower portion  173  of the arcuate shield structure  185  and the transverse piece  167  of the receptacle apparatus manipulating structure  166 . As the shaft  234  rotates, the position of the portion of the wobbler plate  232  engaged with the receptacle apparatus  160  varies in a linearly oscillating manner to impart a linear oscillating motion to the reaction receptacle apparatus  160 .  
         [0061]    The raised ridges  171 ,  172  provided in the middle of the convex surfaces of the transverse piece  167  and the lower portion  173 , respectively, can minimize the surface contact between the wobbler plate  232  and the convex surfaces, thus limiting friction therebetween. It has been determined, however, that raised ridges  171 ,  172  can interfere with the engagement of the manipulating hook  34  of a manipulating device  20  with the apparatus manipulating structure  166 . Therefore, raised ridges  171 ,  172  are preferably omitted.  
         [0062]    In the preferred embodiment of the reaction receptacle apparatus of the present invention, a linear array of individual receptacles  162  are integrally coupled together by the connecting rib structure  164 . The broadest aspects of the present invention, however, contemplate a reaction receptacle apparatus  260 , as shown in FIG. 15, which comprises a single receptacle  262  having an open-mouth  261  and a connected contact-limiting element holding structure, such as tiplet holding structure  276 , attached to the receptacle  262 . In the embodiment illustrated in FIG. 15, tiplet holding structure  276  includes a tiplet receiving orifice  279 , a longitudinal slot  278 , and an end-face  277  forming a portion of an annulus. Alternatively, the contact-limiting element holding structure may be in the form of tiplet holding structure  176  of FIG. 1, in which no longitudinal slot is formed therein and in which a plurality of longitudinally extending raised ribs  154  (see FIG. 3) are formed on the inner surface of the orifice  150 .  
         [0063]    A further alternate embodiment of the reaction receptacle apparatus of the present invention is generally designated by reference number  360  in FIG. 16. As shown in the drawing, the preferred embodiment of reaction receptacle apparatus  360  includes a plurality of individual receptacles  362 , each having an open receptacle mouth  361 . The most preferred embodiment of the reaction receptacle apparatus  360  includes five individual receptacles  362 . Individual receptacles  362  are connected to one another by a connecting rib structure  364 .  
         [0064]    Reaction receptacle apparatus  360  is in most respects identical to the reaction receptacle apparatuses described above and shown in FIGS. 1, 4, and  5 , except that reaction receptacle apparatus  360  does not include contact-limiting holding structures  176  ( 76 ) associated with each individual receptacle  362 . Nor does reaction receptacle apparatus  360  include a contact-limiting element, such as tiplet  170 , associated with each individual receptacle  362 .  
         [0065]    Reaction receptacle apparatus  360  also preferably includes a label-receiving structure  374  having an upper portion  377  and a lower portion  375  cooperating so as to define a flat label-receiving surface  376 . A vertical gusset wall  378  extends between the upper portion  377  of label-receiving structure  374  and the outer wall of the endmost individual receptacle  362 .  
         [0066]    In addition, reaction receptacle apparatus  360  includes an arcuate shield structure  385  having an upper portion  369  and a lower portion  373 . A receptacle apparatus manipulating structure  366  includes a transverse piece  367  connected to the arcuate shield structure  385  by means of a plate  368  extending between upper portion  369  of arcuate shield structure  385  and transverse piece  367 , and a gusset wall  383  extending between the lower portion  373  of the arcuate shield structure  385  and the transverse piece  367  of the receptacle apparatus manipulating structure  366 . As with the previous embodiments, the transverse piece  367  and the lower portion  373  of the arcuate shield structure  385  preferably have mutually-facing convex surfaces, and the surfaces may include vertical arcuate ridges  371  and  372 , respectively. The receptacle apparatus manipulating structure  366  and the arcuate ridges  371  and  372  of the reaction receptacle apparatus  360  serve the same function as the receptacle apparatus manipulating structure  166  and the raised arcuate ribs  171  and  172  described above.  
         [0067]    The reaction receptacle apparatus  360  may further include connecting walls  380  extending between adjacent individual receptacles  362  at upper portions thereof above the connecting rib structure  364 . In addition, a gusset wall  382  may be provided between the endmost individual receptacle  362  and the arcuate shield structure  385 . Finally, the reaction receptacle apparatus  360  may further include lateral ribs  390  extending vertically along the outer surfaces of diametrically opposed positions of upper portions of the individual receptacles  362 . The lateral ridges  390  of the reaction receptacle apparatus  360  serve the same function as do the lateral ribs  190  described above.  
         [0068]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but, on the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Thus, it is to be understood that variations in the particular parameters used in defining the present invention can be made without departing from the novel aspects of this invention as defined in the following claims.