Abstract:
A multiwell plate device is provided having a frame, a substantially flat substrate and a multiwell structure supported by the substrate. The multiwell structure includes multiple bottomless wells formed therein. The substrate is supported by the frame and may be processed by an automated arrayer or instrument that is used to print or spot arrays in a pattern on a reaction surface of the substrate. Thereafter, the multiwell structure may be engaged with the substrate and the multiwell structure and substrate may be engaged with the frame in an upright orientation. For scanning or other analysis, the multiwell structure and substrate may be disengaged from the frame, inverted 180°, and then reengaged with the frame in the inverted orientation.

Description:
[0001]    The present application claims the filing benefit of U.S. Provisional Ser. No. 60/930,121, filed May 14, 2007, and U.S. Provisional Ser. No. 60/963,585, filed Aug. 6, 2007, the disclosures of which are hereby incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to a multiwell plate device and the method for scanning a reaction surface from above and/or below. 
       BACKGROUND OF THE INVENTION 
       [0003]    Multiwell plate devices serve a broad spectrum of laboratory uses. Most applications involve attachment or immobilization of biological materials including, without limitation, biomolecules such as polypeptides and nucleic acids, cells, tissues or fragments biological material, to a surface within the wells (sidewall and/or bottom surface) and the performance of one or more reactions followed by some sort of quantitative and/or qualitative analytical process. 
         [0004]    Robotic instruments have been developed for performing automated processing of multiwell plates. Such automated processes include, without limitation, deposition of biological materials (spotting, printing, etc.), addition or removal of reagents, washing, scanning and analysis. The capability of such automated instruments is typically limited to processing plates with “standard” dimensions as established by the Society of Biomolecular Sciences (SBS Standards). Thus, the “footprint” for most multiwell plates is approximately 85 mm×125 mm with wells located in a standardized format depending upon the total number of wells. The American National Standards Institute (ANSI) has published the SBS Standards for microplates as: “Footprint Dimensions” (ANSI/SBS 1-2004), “Height Dimensions” (ANSI/SBS 2-2004), “Bottom Outside Flange Dimensions” (ANSI/SBS 3-2004) and “Well Postions” (ANSI/SBS 4-2004). All of these ANSI/SBS publications are incorporated herein by reference. 
         [0005]    Although a standard structure for multiwell plates has facilitated automatic robotic processing, at the same time the structure presents a challenge with regards to certain types of procedures, particularly as the number of wells grows beyond 96. For example, spotting or printing of a microarray on the bottom surface of a well using automatic/robotic liquid handling systems or “arrayers” requires the pin or stylus or other printing/spotting means to move significantly up and down as it arrays one well and moves to the next to print or spot another array. Such movement increases processing time and increases the risk of damage to printing pins or stylus from unwanted collision with plate features above the surface to be printed or arrayed. Therefore, a need exists for a multiwell plate device more conducive to rapid processing. 
         [0006]    Moreover, analysis of reactions occurring in the wells of a multiwell plate presents a challenge. Often, the analysis is accomplished by detecting or measuring a change in the material attached to the bottom surface of the wells (substrate) rather than a change in a fluid reaction mixture contained within the wells, as is the case for ELISA-type assays. 
         [0007]    Optical detection is the most commonly utilized method to detect changes in surface-localized reactions, particularly with regards to arrays representing multiple different reactions. For surface-localized reactions, the focal plane for proper measurement of the reaction is often limited to a very small range of depths, typically a range of no more than about 5 mm. Analysis, whether done via automated scanning or microscopy or other means, can be performed by directing a light or energy source from above the reaction surface of the substrate or from below (through the substrate) and focusing an optic that captures the detectable signal from above or below the reaction surface. In some cases, for example when certain types of coated substrates and/or mixtures of detection agents are used, analysis from both above and below the reaction surface is useful in order to glean optimal data. However, the design of a standard multi-well plate complicates efforts to analyze results from both above and below the reaction surface. Most automatic scanners/analyzers can scan from only above or below the reaction surface but not both. Because of the dimensions of a standard multiwell plate, the focal plane of the reaction surface (bottom surface of the wells) when the plate is upright is significantly different from the focal plane when the plate is turned over. One prior art solution has been to use two separate analysis systems wherein one is capable of scanning from above the reaction surface and the other from below. Such an approach is expensive and time-consuming. Alternatively, another solution has been use of a multiwell plate device comprising separate pieces assembled to form the plate including a substrate that is detachable from the multiwell plate structure to eliminate physical interference by the plate structure with the focal plane of the reaction surface. 
         [0008]    U.S. patent application Ser. No. 10/739,784 to Harvey et al., incorporated herein by reference, teaches the use of 1-4 glass microscope slides placed into a frame-like holder having standard multiwell plate dimensions. The slides are spotted or printed prior to placement in the holder. Once in place in the holder, each slide is topped in a releasable manner with a separate multiwell chamber plate having bottomless wells such that the printed glass slide forms a bottom surface for the chamber plate. Finally a retention means is used to retain the slides in the holder. After processing, the chamber plates and slides are removed from the holder and separated, and each slide is analyzed. Thus, the frame-like holder is used only during the reaction phase of the process; the steps of printing arrays and analyzing results are performed on each individual slide while separated from the holder. 
         [0009]    U.S. patent application Ser. No. 11/134,449 to Haines et al., incorporated herein by reference, teaches a device comprising a substrate with a functional coating and biomolecules attached thereto. The substrate is reversibly attached to a superstructure containing multiple openings (multiwell structure). A frame-like tray holds the substrate and serves as an alignment jig for the superstructure. After processing, the system is completely disassembled to remove the substrate for analysis. Thus, the assembled device is used during the reaction phase of the procedure and, optionally, during the step of printing arrays, but it is disassembled for analysis. 
         [0010]    U.S. Pat. No. 7,063,979 to MacBeth et al., incorporated herein by reference, teaches a microtiter-microarray device comprising a bottomless multiwell plate structure, one or more substrates having predeposited microarrays, and one or more gaskets for sealing the substrates to the multi-well plate structure. The seal must be fluid-tight but may be either reversible or irreversible. The patent teaches use of a first aligning device to align the gasket and plate structure for attachment purposes and a second aligning device for attachment of the substrates bearing predeposited microarrays. A separate device is used to remove the substrate after processing for analysis via conventional slide scanner. Alternatively, the substrate can remain attached to the gasket and plate structure for analysis via plate scanner, for example, Tecan LS-200 scanner (Tecan, Durham, N.C.). Thus, the reaction surface in a fully assembled multiwell plate device falls within a particular focal plane when the plate is upright and a significantly different focal plane when turned over. As described in U.S. Pat. No. 7,063,979, to scan the reaction surface from the opposite side with a plate scanner, the substrate must be detached and turned over 180°. 
         [0011]    A detachable substrate presents a challenge because it must be attached to the plate structure in such a way as to be fluid-tight during the reaction phase of processing and yet removable without a level of force that could break or otherwise damage the substrate and without leaving adhesive or other material that might interfere with analysis. A need exists for a multiwell plate device wherein the reaction surface can be scanned from above or below while maintained within the detectable focal plane of a scanning device without requiring detachment of the substrate from the multiwell plate structure. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention overcomes the foregoing and other shortcomings and drawbacks of multiwell plate devices heretofore known. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention. 
         [0013]    In accordance with one embodiment of the present invention, a multiwell plate device is provided having a frame, a substantially flat substrate including a reaction surface and an opposite bottom surface, and a multiwell structure supported by the substrate. The multiwell structure has multiple bottomless wells formed therein and may be engaged with the reaction surface of the substrate using an adhesive layer. In one embodiment, the frame includes a top surface and defines an opening therethrough. A substrate engaging member, such as a ledge or projection by way of example, is disposed adjacent at least a portion of the opening and has a top surface and an opposite bottom surface. 
         [0014]    During use of the multiwell plate device, the substrate may be first placed on the substrate engaging member with the substrate contained by the opening in the frame. In one embodiment, the reaction surface of the substrate is substantially flush with a top surface of the frame so that the reaction surface of the substrate may be manually processed or processed in an automated manner by an arrayer or other instrument that is used to print or spot arrays in a pattern that matches the SBS Standard pattern of wells, or in any other desired pattern. 
         [0015]    After the substrate has been printed or spotted or otherwise processed, the multiwell structure is attached to the reaction surface of the substrate while the substrate is retained on the frame. After the multiwell structure and substrate are attached, they are lifted from the frame and the multiwell structure is then at least partially inserted through the opening from beneath the frame with the reaction surface of the substrate engaging the bottom surface of the substrate engaging member. In this configuration, the multiwell plate device is ready for conventional use. 
         [0016]    In accordance with one aspect of the present invention, the multiwell plate device is reconfigurable for scanning or other analysis. In particular, the multiwell structure and attached substrate may be removed from the frame through application of a manual force to the multiwell structure. Following disengagement from the frame, the multiwell structure and substrate may then be inverted 180° so that the open ends of the wells are now facing down with the multiwell structure located beneath the substrate. In this inverted orientation, the multiwell structure may be least partially inserted through the opening from above the frame so that the reaction surface of the substrate now engages the top surface of the substrate engaging member. 
         [0017]    The frame and multiwell structure may have cooperating alignment structures to assist in aligning the multiwell structure relative to the frame while the multiwell structure is at least partially inserted through the opening from above and beneath the frame. 
         [0018]    In one embodiment, the bottom surface of the substrate is generally flush with the top surface of the frame when the multiwell plate and substrate are inverted and engaged with the frame in the inverted orientation. The invertible configuration of the multiwell structure and substrate relative to the frame allows the reaction surface of the substrate to be scanned from both above or below while being maintained within the detectable focal plane of a scanning device without requiring detachment of the substrate from the multiwell structure. 
         [0019]    According to another aspect of the present invention, a multiwell plate device is provided having a frame defining an opening therethrough, a substantially flat substrate including a reaction surface and an opposite bottom surface, a multiwell structure supported by the substrate, and at least one projection extending upwardly from the frame. The multiwell structure has multiple bottomless wells formed therein and may be engaged with the reaction surface of the substrate using an adhesive layer. 
         [0020]    A substrate receiving surface is disposed adjacent at least a portion of the opening and the at least one projection is positioned outwardly of the substrate receiving surface. The multiwell structure has a pocket formed on a lower side thereof for receiving the substrate therein with the reaction surface of the substrate engaging the multiwell structure. The multiwell structure also includes at least one recess formed on an upper side thereof. 
         [0021]    During use of the multiwell plate device according to this embodiment, the substrate is placed on the substrate receiving surface and the substrate may then be manually processed or processed in an automated manner by an arrayer or other instrument that is used to print or spot arrays in a desired pattern on the reaction surface of the substrate. Thereafter, the multiwell structure is engaged with the reaction surface of the substrate by applying downward pressure to the multiwell structure while the substrate is retained on the frame. In this upright orientation of the multiwell structure and substrate, the bottom surface of the substrate engages the substrate receiving surface with the substrate received within the pocket. In this configuration, the multiwell plate device is ready for conventional use. 
         [0022]    In accordance with another aspect of the present invention, the multiwell plate device is reconfigurable for scanning or other analysis. In particular, the multiwell structure and attached substrate may be removed from the frame through application of a manual force to the multiwell structure and substrate. Following disengagement from the frame, the multiwell structure and substrate may then be inverted 180° so that the open ends of the wells are now facing down with the multiwell structure located beneath the substrate. In this inverted orientation, the multiwell structure may be reengaged with the frame with the least one projection received in the at least one recess formed on the upper side of the multiwell structure. 
         [0023]    The invertible configuration of the multiwell structure and substrate relative to the frame in this embodiment allows the reaction surface of the substrate to be scanned from both above or below while being maintained within the detectable focal plane of a scanning device without requiring detachment of the substrate from the multiwell structure. 
         [0024]    The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
           [0026]      FIG. 1  is a perspective view of a frame component of a multiwell plate device according to one embodiment of the present invention. 
           [0027]      FIG. 2  is a top view of the frame with a transparent substrate in place. 
           [0028]      FIG. 3  is an exploded view of a multiwell structure, an adhesive carrier layer and the substrate contained in the frame prior to assembly. 
           [0029]      FIG. 4  is another view of the components shown in  FIG. 3 . 
           [0030]      FIG. 5  is a perspective view of the multiwell structure attached to the substrate while contained within the frame. 
           [0031]      FIG. 6  is a cut-away view of the multiwell structure attached to the substrate while contained within the frame. 
           [0032]      FIG. 7  is a view of the multiwell structure with attached substrate being positioned into the frame from below. 
           [0033]      FIG. 8  is a perspective view of the assembled multiwell plate device. 
           [0034]      FIG. 9  shows the multiwell structure with attached substrate removed from the frame and inverted 180° for reinsertion into the frame. 
           [0035]      FIG. 10  is a perspective view of the inverted plate assembly. 
           [0036]      FIG. 11  is a perspective view of an alternative multiwell structure having square wells. 
           [0037]      FIG. 12  is an exploded view of a multiwell structure, substrate and frame prior to assembly according to another embodiment of the present invention. 
           [0038]      FIG. 13  is a further exploded view of the multiwell structure, substrate and frame shown in  FIG. 12  prior to assembly. 
           [0039]      FIG. 14  is a perspective view of the assembled multiwell plate of  FIGS. 12 and 13 . 
           [0040]      FIG. 15  is a cross-section of the assembled multiwell plate shown in  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0041]    The present invention, in one aspect, is a multiwell plate device  10  (see  FIG. 8 ) comprising at least three components: i) a substantially flat substrate  12 , ii) a bottomless multiwell structure  14  and a frame  16 . In another aspect, the invention is a method for scanning a reaction surface from above and/or below. 
         [0042]    Referring to  FIGS. 1 and 2 , the frame  16  has an open area  18  used to contain the substrate  12  for processing in an automated array printer or other instrument or for manual processing. In a preferred embodiment, the frame  16  has a “footprint” that conforms to the standard dimensions for multiwell plates (SBS Standards), for example, 85.5×127.6 mm. The open area  18  in the frame  16  may vary depending upon the size of the substrate  12  but preferably should be sized so that it nearly matches the dimensions of the substrate  12  to prevent detrimental movement or shifting of the substrate  12  during processing. For example, if using a substrate  12  of about 75.7 mm×111.3 mm, an open area  18  of about 75.8 mm×111.4 mm is suitable. 
         [0043]    The substrate  12  rests upon ledges  20  or other protrusions on the inner surfaces  22  of the frame  16 . Preferably, the depth of the ledges  20  from a top surface  24  of the frame  16  is approximately equal to the thickness of the substrate  12  such that a reaction surface  26  of the substrate  12  as it sits in the open area  18  is essentially flush with the top surface  24  of the frame  16 . For example, if the substrate  12  is 1 mm in thickness, the ledges  20  are preferably located about 1 mm below the top surface  24  of the frame  16 . 
         [0044]    Once the substrate  12  is in place in the open area  18  of the frame  16 , an automated arrayer or instrument is used to print or spot arrays in a pattern that matches the SBS Standard pattern of wells, or any other desired pattern, without the need for wasted vertical movement typically needed when printing or spotting the bottom of a conventional multiwell plate. 
         [0045]    Referring to  FIGS. 3-6 , after the substrate  12  is printed or spotted or otherwise processed, the bottomless multiwell structure  14  is attached to the reaction surface  26  of the substrate  12  while in place on the frame  16 . Preferably, the dimensions of the multiwell structure  14  are smaller than those of the substrate  12  so that the substrate  12  forms a perimeter  28  (as shown in  FIG. 9 ) around the multiwell structure  14 . For example, if the substrate  12  is about 75.7 mm×11.3 mm, the multiwell structure  14  might be about 73 mm×108.6 mm. 
         [0046]    In one embodiment, the multiwell structure  14  has two or more lateral projections  30  each with a downwardly extending portion serving as alignment tabs  32  that mate with alignment receptors  34  in the frame  16  to guide the placement of the multiwell structure  14  onto the substrate  12  so that the wells  36  of the multiwell structure  14  correspond with the printed or spotted areas of the substrate  12 . The size, shape and number of the lateral projections  30 , alignment tabs  32  and corresponding alignment receptors  34  may be varied as long as multiwell structure  14  can be placed onto the reaction surface  26  of the substrate  12  with sufficient accuracy in relation to the arrays or other material contained on the substrate  12 . 
         [0047]    In one embodiment, the surface  38  (see  FIGS. 4 and 5 ) of the multiwell structure  14  that contacts the substrate  12  contains a pre-applied adhesive (not shown). A removable liner (not shown) may be used to protect the adhesive layer until time of use. In another embodiment, shown in  FIGS. 3 and 4 , a thin flat adhesive carrier layer  40  is used to attach the multiwell structure  14  to the substrate  12 . For example, the carrier layer  40  has adhesive on both sides and forms an intervening layer between the multiwell structure  14  and the substrate  12 . For convenience, the multiwell structure  14  can be supplied with the carrier layer  40  already attached to its surface  38 . 
         [0048]    When the alignment tabs  32  are inserted into the alignment receptors  34  in the frame  16 , downward pressure may be applied to the multiwell structure  14  to affect a functional seal or attachment to the substrate  12 . 
         [0049]    Referring to  FIGS. 7 and 8 , after the multiwell structure  14  and substrate  12  are attached, they are lifted from the frame  16  and then reinserted from underneath the frame  16  with the open end of the wells  36  facing upward through the open area  18  in the frame  16 . The lateral projections  30  of the multiwell structure  14  facilitate alignment by fitting into the alignment receptors  34  or other receptive features in the frame  16 . The multiwell structure  14  with attached substrate  12  is pushed upward through the open area  18  of the frame  16  until the reaction surface  26  of the substrate  12  abuts the underside of the ledges  20  provided on the inner sidewall  22  of the frame  16 . 
         [0050]    In one embodiment, the multiwell structure  14  and/or the lateral projections  30  fit snugly to hold the multiwell structure  14  securely in the frame  16 . Optionally, features on the internal sidewalls  22  of the frame  16  (not shown) may be used to secure or enhance the fit. The multiwell plate device  10  assembled in this mode can be used in substantially the same way as a conventional single-piece multiwell plate device. 
         [0051]    For scanning or other analysis, the multiwell place device  10  may be used as shown in  FIG. 8 . Alternatively, the multiwell structure  14  with the substrate  12  attached may be removed from the frame  16  through application of manual force to the multiwell structure  14  and then inverted 180° so that the open ends of the wells  36  are facing down and the substrate  12  is on top, as shown in  FIG. 9 . 
         [0052]    Continuing with  FIGS. 9 and 10 , the multiwell structure  14  is inserted into the open area  18  in the frame  16  from above and lowered so that the substrate  12  comes to rest on the top surface of the ledges  20  provided on the inner sidewalls  22  of the frame  16 . The reaction surface  26  of the substrate  12  is now at the level of the top surface of the ledges  20  whereas in the other format or “mode” (with the multiwell structure  14  facing up), the reaction surface  26  is at the level of the bottom surface of the ledges  20 , thus the focal plane differs only by the thickness of the ledges  20 . The thickness of the ledges  20  is generally influenced by the material used to form the frame  16  since the material strength of the ledges  20  must be sufficient to bear the weight of the multiwell structure  14  and substrate  12 . Typically, a thickness of about 0.3-1.0 mm is adequate for most materials suitable for manufacturing the frame  16 . 
         [0053]    Now referring to an alternative embodiment of the present invention, a multiwell plate device  100  is shown in  FIGS. 12-15  comprising at least three components: i) a substantially flat substrate  102 , ii) a bottomless multiwell structure  104  and a frame  106 . In another aspect, the invention is a method for scanning a reaction surface from above and/or below. 
         [0054]    Referring to  FIG. 12 , the frame  106  has an open area  108  used to contain the substrate  102  for processing in an automated array printer or other instrument or for manual processing. In a preferred embodiment, the frame  106  has a “footprint” that conforms to the standard dimensions for multiwell plates (SBS Standards), for example, 85.5×127.6 mm. The open area  108  in the frame  106  may vary depending upon the size of the substrate  102  but preferably should be sized so that it nearly matches the dimensions of the substrate  102 . For example, as shown in  FIG. 12 , if using a substrate  102  of about 75.7 mm×111.3 mm, an open area  108  of about 75.5 mm×111.1 mm permits the substrate  102  to rest upon a receiving surface  110  of the frame  106 . In one embodiment, the receiving surface  110  is slightly elevated compared to the remaining outer surface  112  of the frame  106  as shown in  FIG. 15 . 
         [0055]    To minimize movement of the substrate  102  while positioned on the frame  106 , one or more ridges  114  or other protrusions may be included on the frame  106 .  FIG. 12  shows ridges  114  on each of the four sides of the frame  106 , but variations are contemplated, including a continuous ridge surrounding the entire open area  108  or multiple ridges  114  on the same side or the ridges  114  may be limited to fewer than all four sides of the frame  106 . 
         [0056]    In the embodiment shown in  FIG. 15 , the height of a ridge  114  is greater than the thickness of the substrate  102  such that the ridge  114  defines the receiving surface  110  for the substrate  102  adjacent the open area  108 . For example, if the substrate  102  is 1 mm in thickness, the ridges  114  may be about 2.8 mm in height above the outer surface  112  of the frame  106 . The receiving area  110  is elevated compared to the remaining outer surface  112  of the frame  106 . The ridges  114  also permit the multiwell structure  104  to fit securely to the frame  106  without adhesive contact between the multiwell structure  104  and the frame  106 . Further, the ridges  114  mate with one or more grooves  116  in the top surface  118  of the multiwell structure  104  when the structure  104  with attached substrate  102  is used in an inverted format. 
         [0057]    For additional ease in assembling the device, optional structural features may be included on the substrate  102  and/or the frame  106  that permit the substrate  102  to fit into the frame  106  in only one orientation. For example, a corner of the substrate  102  and a corresponding corner of the frame  106  may be angled or notched to permit a matched fit (not shown). Alternative means of dictating orientation are contemplated. 
         [0058]    Once the substrate  102  is in place in the open area  108  of the frame  106 , and optionally before the multiwell structure  104  is placed onto the substrate  102 , an automated arrayer or instrument is used to print or spot arrays in a pattern that matches the SBS Standard pattern of wells, or any other desired pattern (not shown). The positioning of the substrate  102  in the frame  106  also serves to properly locate the substrate  102  relative to the X, Y stops which are standard on arrayer platforms (not shown). 
         [0059]    After the substrate  102  is printed or spotted or otherwise processed, the bottomless multiwell structure  104  is attached to a reaction surface  120  of the substrate  102  while in place on the frame  106 . In the embodiment shown in  FIGS. 12-15 , the dimensions of the multiwell structure  104  are greater than those of the substrate  102  so that the multiwell structure  104  fits over the ridges  114  on the frame  106 . 
         [0060]    As shown in  FIGS. 12 ,  13  and  15 , the multiwell structure  104  has the top surface  118 , a bottom surface  124  and four sidewalls  126 . The bottom surface  124  provides the surface for attachment to the reaction surface  120  of the substrate  102 . Since the sidewalls  126  fit flush against the frame  106  when assembled, a recessed area or “pocket”  128  is provided in the bottom surface  124  to accommodate the thickness of the substrate  102 . For example, if the substrate  102  is about 1 mm in thickness, the pocket  128  is at least 1 mm in depth to provide additional allowance for adhesive, so that the bottom surface  124  of the multiwell structure  104  makes full contact with the substrate  102  via an intervening adhesive layer  130  when assembled. The ridges  114  may serve as alignment guides for the multiwell structure  104  to guide the placement of the multiwell structure  104  onto the substrate  102  so that the wells  132  of the multiwell structure  104  correspond with the printed/spotted areas of the substrate  102 . 
         [0061]    In one embodiment, the bottom surface  124  of the multiwell structure  104  that contacts the substrate  102  contains a pre-applied adhesive (not shown). A removable liner (not shown) may be used to protect the adhesive layer until time of use. Alternatively, a thin flat adhesive carrier layer (not shown) is used to attach the multiwell structure  104  to the substrate  102 . For example, the carrier layer has adhesive on both sides and forms an intervening layer between the multiwell structure  104  and the substrate  102 . For convenience, the multiwell structure  104  can be supplied with the carrier layer already attached to its bottom surface  124 . 
         [0062]    When the ridges  114  are inserted into the pocket  128  in the bottom surface  124  of the multiwell structure  104 , downward pressure may be applied to the multiwell structure  104  to affect a functional seal or attachment to the substrate  102  via the adhesive  130 , as shown in  FIG. 15 .  FIG. 14  shows the fully assembled plate device  100 . The multiwell plate device  100  assembled in this mode can be used in substantially the same way as a conventional single-piece multiwell place device. 
         [0063]    Alternatively, the multiwell structure  104  with the substrate  102  attached may be removed from the frame  106  through application of manual force to the multiwell structure  104  and then inverted 180° so that the open ends of the wells  132  are facing downward and the substrate  102  is on top. The multiwell structure  104  may then be attached to the frame  106  by aligning the ridges  114  on the frame  106  with the grooves  116  in the top surface  122  of the multiwell structure  104  so that the sidewalls  126  are flush against the frame  106 . 
         [0064]    With regards to manufacture, the substrates  12 ,  102  may be made from any substantially flat material useful for containing biological materials. In a preferred embodiment, the substrate is glass, but alternatively, silicon, quartz, plastics, metals or other materials may be used. Further, part or all of the substrates  12 ,  102  may be treated and/or coated with other chemicals or compounds to enhance qualities including, without limitation, binding capacity or specificity, as is known in the art, or the substrates  12 ,  102  may be uncoated/untreated. Also, the substrates  12 ,  102  may be transparent, translucent or opaque or any combination of the above. While the present invention has been exemplified as having a single substrate  12 ,  102 , multiple smaller substrates may be utilized (not shown). For example, multiple glass microscope slides could be substituted for a single substrate. Further, the thickness of the substrates  12 ,  102  can be varied. Typically, a substrate  12 ,  102  with a thickness in the range of 0.3 mm-1.0 mm is suitable for many uses but the thickness can be increased or decreased. 
         [0065]    An optional feature of the substrate  102  is a bar code or other indicia  134  (see  FIGS. 12 and 14 ) to facilitate identification, inventory, tracking, processing and/or other aspects of the handling of the substrate  102  and/or assembled multiwell plate  100 . To facilitate viewing of the indicia  134  an aperture or window  136  (see  FIG. 12 ) may be provided in the multiwell structure  104  or frame  106 . 
         [0066]    The multiwell structures  14 ,  104  can be made from any moldable material, such as a plastic polymer, and may be rigid or flexible. Material cost may be a factor because the multiwell structures  14 ,  104  are ideally disposable after use. By way of non-limiting example, polystyrene, polypropylene and the like provide suitable materials for the multiwell structures  14 ,  104 . Dimensions of the multiwell structures  14 ,  104  may vary depending upon the width and length of the substrates  12 ,  102  or composite of multiple substrates. Further, the wells  36 ,  132  of the multiwell structures  14 ,  104  should be formatted to meet SBS Standards. The depth of the wells  36 ,  132  may conform to SBS Standards or alternatively, shallow depths are suitable. In one embodiment, the depth of the wells  36 ,  132  in the multiwell structures  14 ,  104  is no more than 5 mm (more shallow than SBS Standards). Further, the shape of the wells  36 ,  132  may be round as shown in  FIGS. 3-10  and  12 - 14  or they may be some other shape such as square-shaped as shown in  FIG. 11 . 
         [0067]    The frames  16 ,  106  are molded or machined from any number of materials including, without limitation, plastic polymers, acrylics and metals. The frames  16 ,  106  may be disposable or reusable depending upon the durability of the material used, cost, etc. The height of the frames  16 ,  106  may conform to SBS Standards or it can be varied according to the depth of the multiwell structures  14 ,  104 . For example, if the multiwell structures  14 ,  104  are about 4-5 mm in depth, an appropriate height for the frame  16  is about 13.5-14.0 mm and the appropriate height for the frame  106  is about 5.0-14.0 mm. 
         [0068]    The optional adhesive carrier layer  40  may comprise a film or resilient gasket-like material such as silicone or closed-cell polyethylene foam and the like. Preferably the adhesive used to attach the substrates  12 ,  102  to the multiwell structures  14 ,  104  is irreversible but alternatively, a reversible adhesive may be more appropriate for certain uses. Likewise, a combination of irreversible adhesive on one side of the carrier layer  40  and reversible adhesive on the other side may be used. Adhesives of these types are known in the art. 
         [0069]    Other embodiments of the invention may be apparent to those skilled in the art and are considered to be part of the scope and spirit of the present invention. The descriptions and examples provided herein are intended to be exemplary and not limiting with regards to the scope of the invention. 
         [0070]    While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants&#39; general inventive concept.