Abstract:
A vial plate includes a base plate having protrusions spaced from each other to form compartments for supporting vials and openings which allow the flow of liquids or gases to heat or cool the vials. The vial plate may have a cover and use a multi-tiered structure having one or more spacers which attach to the base plate, each other, or the cover to vary the height of the vial plate for accommodating vials of different sizes. The vial plate does not float in water, can accommodate vials containing volatile solvents, and can support individual vials.

Description:
TECHNICAL FIELD 
     The present invention relates generally to devices used in analytical chemistry assays and, more particularly, to plates for holding vials used in analytical chemistry assays. 
     BACKGROUND OF THE INVENTION 
     Analytical chemistry laboratories use a variety of different sized and shaped vials for different types of experimental assays, including sorbent assays, high-throughput screening assays, and combinatorial chemistry analysis. In those assays, there is a need to provide support for the vials used. Often, the support is necessary to maintain the vials in an upright position to facilitate chemical reactions, prevent assay fluids from escaping from the vials, enable movement of the vials without disturbing the assay, or meet other experimental considerations. Various vial-holding devices, such as microplates, have been used for assays performed in these laboratories, optionally used in autosamplers. Generally, these devices contain multiple compartments for insertion of and providing support for vials. 
     Moreover, certain conventional devices will not allow for insertion and support of individual vials, but will only properly support a series of connected vials for microassays. In instances when less than a series of vials are to be used in an assay, these devices prevent the use of the assay or require that the whole series of vials be used, thus, wasting the unused vials of the series. 
     Generally, vials used in analytical chemistry assays are made of glass or plastic, among other suitable materials. Many of the assays performed in analytical chemistry laboratories require heating or cooling of the vials to simulate in vitro conditions or temperature sensitive experiments, or mimic in vivo conditions. The heating or cooling is usually done using liquids or gases. Often, to heat or cool the vials, the exterior of each vial is immersed in fluids (liquids or gases) having various temperatures, such as in a hot water bath. Some of the conventional vial-holding devices float in water so that they are unstable in a water bath and require the use of other instruments to stabilize them. This requirement can significantly affect the conditions under which an assay is to be performed or it may render useless the results of an assay. 
     Also, in many assays, uniform heating or cooling of all of the sample vials is desired. Many conventional vial-holding devices do not allow direct contact of all of the vials with the heating or cooling medium, thus preventing uniform changes in temperature within the vials. In addition, many of the conventional devices do not allow for use with volatile solvents because these solvents attack the vial holders. 
     Devices commonly used for holding vials include blocks, boxes, deep well plates, and microplates, such as well plates and microtiter plates, some of which may use covers. These microplates are generally used for antibody assays, such as ELISA, and can hold 96 or 384 vials or other multiples of, for example, 96. Many of the conventional microplates or vial holders contain specifically shaped compartments which do not allow for insertion of certain types of vials. 
     Deep well plates are usually made of polypropylene and retro-fitted with glass vials. These plates are often translucent and used in high-throughput drug screening and combinatorial chemistry analysis. Nevertheless, these plates cannot be used with certain volatile solvents. 
     Thus, there is a need for a vial-holding device which can accommodate individual vials of different shapes and sizes, be used with volatile solvents, maintain its position at the bottom of a water bath, and allow uniform transfer of heat to and from the vials. 
     SUMMARY OF THE INVENTION 
     To meet this and other needs, and in view of its purposes, the present invention provides a vial plate for holding vials. The plate of the present invention can have varying heights. It can have a fixed height or it can be multi-tiered for adjustable height to support different sized vials. The plate of the present invention can contain a cover for the vials. 
     A preferred embodiment for the plate of the present invention contains a base plate for holding certain sized vials and spacers that attach to the base plate to increase its height for support of tall vials. The plate of the present invention is constructed of an inert material having a density such that the plate does not float in aqueous liquids. In addition, the vial plate, in combination with a cover having a resilient liner, can accommodate volatile solvents. The vial plate of the present invention contains openings which allow for the flow of thermal energy through the bottom of the base plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawing are the following figures: 
     FIG. 1A is a top view of the base plate of the present invention; 
     FIG. 1B is a side view of the base plate shown in FIG. 1A; 
     FIG. 2A is an exploded side view of the spacer of the present invention; 
     FIG. 2B is an exploded side view of the spacer through section  2 B— 2 B of FIG. 2A; 
     FIG. 2C is an exploded side view of the base plate; 
     FIG. 2D is an exploded side view of the base plate through section  2 D— 2 D of FIG. 2C; 
     FIG. 3A is an exploded side view of the cover, spacer, and base plate attached using slots and tabs; 
     FIG. 3B is an exploded side view of the cover, spacer, and base plate attached using slots and tabs through section  3 B— 3 B of FIG. 3A; 
     FIG. 4A is an exploded side view of the cover, two spacers, and base plate attached using slots and tabs; 
     FIG. 4B is an exploded side view of the cover, two spacers, and base plate attached using slots and tabs through section  4 B— 4 B of FIG. 4A; 
     FIG. 5A is an exploded side view of the cover and base plate attached using slots and tabs; 
     FIG. 5B is an exploded side view of the cover and base plate attached using slots and tabs through section  5 B— 5 B of FIG. 5A; 
     FIG. 6A is a top view of the cover of the present invention; 
     FIG. 6B is a side view of the cover shown in FIG. 6A; 
     FIG. 7A is a top view of the spacer of the present invention; and 
     FIG. 7B is a side view of the spacer shown in FIG.  7 A. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The vial plate of the present invention can support a variety of sized vials by adjusting its height, optionally using a multi-tiered structure. The vial plate can have a fixed height or can use spacers for an adjustable height. The vial plate can accommodate vials of different size, shape, and material and can handle volatile solvents. In addition, the vial plate can support individual vials and can accommodate differing amounts of vials used in different assays. 
     As shown in FIG. 1A, the vial plate  2  includes a base plate  4  having a solid perimeter portion  6  and many protrusions  8  inside of the perimeter portion  6  which form compartments  10  to hold the vials. These compartments  10  allow the base plate  4  to hold one or more individual vials without the need for a series of vials attached to each other. The protrusions  8  may be shaped so that they conform around vials inserted into the compartments  10 . Although not a necessity, the compartments  10  may have scalloped ends  11  where the compartments  10  contact the perimeter  6  of the base plate  4 . Scalloped ends  11  accommodate round vials. 
     In addition, the base plate  4  has openings  12  on its underside to accommodate the flow of thermal energy (hot or cold) from gases or liquids. The openings  12  in the base plate  4  cover at least a part of every vial compartment  10 . Openings  12  may be in the form of channels running parallel to each other along the length, the width, or both the length and the width of the base plate  4  or the channels may intersect each other, such as in a criss-cross or perpendicular pattern. The openings  12  allow the liquids from the assay to contact the vials, not only the vial plate  2 . In addition, openings  12  allow the even flow of thermal energy through the base plate  4  to the vials so that the vials may be uniformly heated or cooled. The base plate  4  is made of plastic, such as a chemically resistant polypropylene, or any other suitable inert material having similar properties, including a density greater than that of water. This density prevents the base plate  4  from floating in a water bath or in other aqueous solutions. Further, the material is inert so that it can handle volatile liquids. 
     A preferred embodiment of the base plate  4 , as shown in FIGS. 2A,  2 B,  2 C, and  2 D, includes slots  14  in the top of its perimeter  6 . These slots  14  are constructed to connect to tabs  18  on either the bottom of spacer  16  or the cover piece  22 . These slots  14  allow the base plate  4  to be secured to spacer tabs  18  or cover lugs  24 . The spacer  16  contacts the base plate  4  around the perimeter portion  6  of base plate  4  and has tabs  18  on the bottom side of spacer  16  for attachment to the base plate  4  or other spacers  16 . In addition, as shown in the top and side views of spacer  16  in FIGS. 7A and 7B, the spacers  16  have slots  20  on their top sides for attachment to tabs  18  from other spacers or, if it is the top spacer which is attached to the cover  22 , to cover lugs  24 . Any number of spacers  16  may be used to increase the height of the vial plate  2  and to allow vial plate  2  to support vials of different sizes. The spacers  16  may be constructed of the same material, having the same density, as the base plate  4 . Thus, a chemically resistant polypropylene plastic or any other suitable material can be used to construct spacers  16 . 
     FIGS. 3A and 3B depict the spacer  16 , base plate  4 , and cover  22  attached to each other. The spacer  16  and base plate  4  are attached through the tabs  18  of the spacer snapping into the slots  14  of the base plate  4 . The tabs  18  may contain a slanted end  19  which secures them within the slots  14 . The spacer  16  is attached to the cover  22  through lugs  24  of the cover  22  snapping into the slots  20  of the spacer  16 . 
     As shown in FIGS. 4A and 4B, the cover  22  may be placed on the top spacer  16  which may be attached to other spacers  16 . The bottom spacer  16  is attached to the base plate  4 . (If a single spacer  16  is used, then spacer  16  is attached to the base plate  4  and may also be attached to the cover  22 .) The spacers  16  are attached to each other through tabs  18  and slots  14  and the cover  22  is attached to the slots  14  through lugs  24 . The cover  22  may have a curved shape, shown specifically in FIGS. 6A and 6B. The cover includes a resilient liner  26  within it and is in a top-hat configuration, such as shown and described in U.S. Pat. No. 5,016,771, the contents of which are incorporated herein by reference in their entirety. The liner  26  may be constructed generally of a rubber material such as silicone, natural or butyl rubber, polyisoprene (natural red rubber), or a polytetrafluoroethylene such as Teflon (a trademark of E. I. DuPont de Nemours &amp; Co., Inc. of Wilmington, Del.), or any combination of those materials. The liner  26  insures sealing of the vial plate  2  and enables use of the vial plate  2  with certain volatile solvents. Further, the liner  26  facilitates puncturing with a needle or syringe and resealing the liner  26  such that it will self-repair a hole formed by such a needle or syringe. 
     FIGS. 5A and 5B depict the cover  22  and base plate  4  attached to each other through the lugs  24  of the cover snapping into the slots  14  of the base plate  4 . The lugs  24  may contain a slanted end  28  which secures lugs  24  within the slots  14 . 
     The vial plate  2  may hold up to 96 or 384 vials, which are common capacities for vial holders used in analytical chemistry assays. Vial plate  2  can accommodate 9 millimeter (mm) tapered, round or flat-bottom vials of various heights, e.g., 16 mm, 32 mm, or 48 mm. For example, the base plate alone would be used for 16 mm vials, the base plate and one spacer would be used for 32 mm vials, and the base plate and two spacers would be used for 48 mm vials. Thus, the multi-tiered vial plate can support 0.5, 1.0, and 1.5 milliliter (ml) vials or other groups of vials with varying heights. The vials that can be used in the vial plate  2  of the present invention can be made of glass, plastic, or other suitable materials. The vials may have different shapes, including round or flat-bottomed, square-shaped, or tapered. 
     The vial plate  2  of the present invention may be used with analytical chemistry assays and vials used in assays related to drug metabolism, screening in combinatorial chemistry, high-throughput screening, and in sorbent assays. Further, the vial plate  2  is compatible with autosamplers used in certain assays. 
     Although the invention is illustrated and described herein, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.