WO2005072875A1 - Deformable sealing compound sheets - Google Patents

Abstract

A sealing sheet (10) made up of a composite plastic sheet (20) with a plurality of deformable cavities (40). The deformable cavities (40) of the sheet (20) provide receptacles in which numerous compounds can be simultaneously dried and thus stored in a stable form. The compounds can be rapidly recovered simultaneously, with a high degree of accuracy, by using the sealing sheet (10) to seal a recovery plate (90), the recovery plate comprising corresponding individual wells (110) containing solvent. Recovery can be enhanced by compressing the deformable cavities, thus facilitating break up of the dried compounds into the solvent.

Description

DEFORMABLE SEALING COMPOUND SHEETS

[0001] This Application claims priority to United States Provisional Application Number 60/539,453, filed January 26, 2004, herein incorporated by reference in its entirety. Field Of The Invention [0002] This invention relates generally to methods and devices for compound storage and recovery. In particular, it relates to compound storage and recovery of compounds in a dried foonat. The storage device and method are especially relevant for parallel processing of compounds where the volumes of the compounds are relatively small. Background Of The Invention [0003] Frequently, the drug discovery process starts with the screening of numerous compounds for the identification of suitable lead chemicals, which upon optimization, can become potential new drugs. Because of the large numbers of compounds examined, the screening process commonly employs some form of high throughput screening (HTS) to rapidly examine large numbers of compounds in order to identify possible lead chemicals and then optimizing those chemicals. While there are a variety of approaches to HTS, many, if not most, of the techniques require that each compound is first dissolved in a solution in order to manipulate the compound. [0004] Traditionally, in order to increase the rate of compound analysis, the philosophy was that one would like to have a large library of predissolved compounds, allowing rapid access to each compound for each run, thus eliminating the time consuming step of dissolving and measuring the compound prior to screening. This would allow ready access to the compounds and increase the throughput speed of the compounds through the screening process. One common solvent that is used to dissolve these compounds is dimethyl sulfoxide (DMSO). DMSO is nearly inert, has a high boiling point, and has good solvent behavior. [0005] However, storing compounds in DMSO has several disadvantages. DMSO is hygroscopic in character, it behaves as an oxidation reagent, and a large amount of air can be dissolved into the solvent, all of which may alter the quality of a compound. Thus, storing compounds in DMSO involves a compromise. If one keeps the lead chemicals dissolved in DMSO, then one has ready access to the compounds; however, the integrity of the compound is at risk. On the other hand, if one stores the compound in a crystalline or dried form, then compound integrity is largely assured; however, access to the compound for testing in the HTS requires the additional time consuming step of dissolving numerous compounds. [0006] There are additional problems associated with keeping the compound stored in a dry format. Each time one dissolves a compound; one runs the risk that not all of the compound will be dissolved, thus, making the concentration of the dissolved compound unknown. Additionally, due to the large numbers of compounds that are repeatedly examined, one wants to use as little compound as possible for each run in order to manage costs. Unfortunately, this results in a situation where one has to dissolve a small amount of compound in a small volume of solution, do so numerous times, at high speed, and a sufficient degree of accuracy and precision. While advanced robotics and engineering may be able to achieve such desirable results, these devices are large and expensive, and the processing rate is necessarily limited by the number of robots available. [0007] Because of this tradeoff between compound integrity, stability, and compound access, and general issues with compound accuracy and precision, improvements in methods of storing and retrieving numerous compounds, especially for use in HTS, have become important in developing approaches to drug discovery. It appears that the approach that industry has chosen to resolve these issues is to dissolve a compound, but to do so in containers that are then sealed under an inert atmosphere. [0008] One approach involves the use of a large amount of a compound, dissolved in a large volume of a solvent, thus creating a stock solution. While having a stock solution of an exact concentration, from which one can allocate smaller samples, is advantageous, it also has its problems. Each time a compound is taken from the stock solution the entire stock solution is at risk of exposure to contaminants and degradation. Additionally, if one were to keep large numbers of such stock solutions, each in a controlled environment, it would be very costly and space consuming. Finally, these large stock solutions are frequently stored at low temperature in order to reduce compound degradation; however, this results in precipitation of the compound and a loss in accuracy and precision. One approach to avoiding the risk of precipitation is to store the compound in DMSO at a very low compound concentration. This reduces the chance that the compound will precipitate out of solution even if water is taken up by the DMSO. However, this also reduces the range of concentrations that one may examine in a HTS, thus making it undesirable. [0009] Another approach is to depend on robots for compound storage and recovery. The robots can work under inert conditions, thus reducing the chance that the DMSO will be compromised by oxygen or water. Additionally, the robots can be designed to pipette and redissolve a dried compound, thus allowing one to store compounds in a dried format. However, robots are generally large and expensive. Additionally, the ability of a robot to dissolve large numbers of small volume, small quantity compounds is limited by the speed and accuracy of the robot. [0010] Another approach has been to create a stock solution and then store small amounts of the dissolved compound in a system known as Microtape [trade]. This tape is actually a roll of thick plastic with 10 microliter wells in the thick plastic roll. The dissolved compounds are placed into each well and then the surface of the tape is durably sealed via a heating process. While this helps to reduce space problems, the device and method may have problems with cross contamination, problems with volume control due to evaporation of solvent and droplets staying on the seal, and require that assays be perfooned in the tape itself, thus making it difficult to perfoon certain assays, such as cellular assays. Additionally, since the compounds are stored in DMSO, this storage technique has many of the same general risks associated with compound integrity and the risk that some of a compound may precipitate out of solution and thus alter the concentration of the compound. [0011] It does not appear that storing small amounts of the compound in a dried format is generally accepted as efficient. Perhaps this is because, in order to test the compound, a compound must be first dissolved. Indeed, this approach could be considered undesirable since the industry assumes that the key to increasing compound processing speed is having the compound already in a liquid format. While dissolving a compound may not be overly time consuming for a single compound, when multiple compounds are to be examined in parallel, this solvation step could become the rate-limiting step in HTS. Additionally, since the volumes tested are usually very small, it is difficult to rapidly dissolve all of a small amount of a compound in a small volume of solvent. Furthermore, even if some of the dried compound dissolved, unless the entire compound dissolved, one would not know the concentration of compound in the final solution. Summary Of The Invention [0012] One embodiment provides a recovery unit that is useful for dissolving numerous dried compounds, simultaneously. The recovery unit comprises a recovery plate, which has a plurality of wells that are open at the top of the plate, and a sealing sheet, which has a plurality of deformable cavities in which samples may be stored in a dried condition. The sealing sheet allows a seal to be fooned between each well and its corresponding deformable cavity. [0013] One embodiment provides a method for drying and dissolving dried samples involving the use of a recovery plate and a sealing sheet. Each wet sample is placed in a deformable cavity of the sealing sheet and dried thus allowing the sample to be stored and later retrieved. Retrieval involves the placement of a solvent in a well of a recovery plate and matching the recovery plate and the sealing sheet together so that the wells of the recovery plate and the deformable cavities communicate with each other. The deformable cavities are then deformed, creating a recovery unit, from which the sample may easily be fully dissolved and recovered. [0014] One embodiment provides for a composite plastic sheet for storing dry compounds, the sheet comprising a layer of metal foil coated on the top and bottom with a layer of plastic. The sheet also contains a plurality of deformable cavities pressed into the sheet in a predetermined arrangement, and at least one dried compound, which is located within a deformable cavity. [0015] One embodiment provides for a library of sealing sheets. [0016] One embodiment provides a method for recovering compounds from a plurality of sealing sheets by matching each sealing sheet with a plate so that the compounds communicate with the wells of the plate, stacking a plurality of such paired sheets and recovery plates on top of one another so that the entire stack may be processed together, compressing the entire stack, and contacting the solvent in the wells with the compounds. One embodiment provides a method for recovering a plurality of dried compounds from a sealing sheet. The method comprises aligning the dried compounds on the sealing sheet with the solvent-containing wells of a plate and then contacting the solvent with the dried compounds. [0017] One embodiment provides a method for solubilizing a library of dried materials comprising taking a substrate with the materials dried in a predetermined pattern and matching the substrate against a multi-well plate in a sealing arrangement so that the dried materials are matched up with the wells of the plate, and then contacting the dried material with the solvent. [0018] One embodiment provides a composite sheet comprising a first layer of a polymer material, a second layer of a metal, a plurality of cavities formed in the sheet by punching or pressing, and a plurality of material samples dried in the cavities of the sheet. [0019] One embodiment provides a sheet with deformable cavities composing a stable, deformable inert sheet, a plurality of deformable cavities created in the sheet, a carrier frame attached to and supporting the sheet, and optionally a plurality of compounds dried in the cavities. Brief Description Of The Drawings [0020] FIG. 1A-1D are different views of a deformable sample sheet and recovery plate of the present invention. [0021] FIG. 1A is a plan view of a multi-layer sealing sheet of the present invention having cavities pressed thereinto. [0022] FIG. IB is a longitudinal cross section of the sample sheet of FIG. 1A, taken along the line B-B. [0023] FIG. 1C is a perspective view of a recovery plate used in the present invention. [0024] FIG ID is a longitudinal cross section of the recovery plate of FIG. 1C, taken along the line D-D. [0025] FIG. 2A-2F are longitudinal cross sections of a process for recovering compound from the sealing sheet of FIG. 1 A. [0026] FIG. 2A illustrates the sealing sheet positioned above a multi-well recovery plate. [0027] FIG. 2B illustrates the sealing sheet sealed over the multi-well plate with a lid to form a recovery unit. [0028] FIG. 2C illustrates inversion of the recovery unit to facilitate dissolution of compounds in solvent in the wells of the recovery plate. [0029] FIG. 2D illustrates dissolution of compound in the recovery unit after agitation. [0030] FIG. 2E illustrates re-inversion and centrifugation to assure compound and liquid remain in wells of the recovery plate. [0031] FIG. 2F illustrates removal of the sealing sheet leaving dissolved compound in the wells of the recovery plate. [0032] FIG. 3 is a plan view one embodiment of a carrier frame. [0033] FIG. 4A is a plan view of one embodiment of a deformable cavity. [0034] FIG. 4B is a longitudinal cross section of the sealing sheet of FIG. 4A, taken along the line B-B [0035] FIG. 4C is a plan view of another embodiment of a deformable cavity. [0036] FIG. 4D is a longitudinal cross section of the sealing sheet of FIG. 4C, taken along the line D-D [0037] FIG. 5A-5C show one embodiment for making the deformable cavities. [0038] FIG. 5A shows a reverse stamp in its relative position above the composite plastic sheet. [0039] FIG. 5B shows the stamp pressed into the sheet until deformable cavities are created. [0040] FIG. 5C shows the resulting deformable sealing compound sheet. [0041] FIG. 6A-6B show an embodiment of an extraction unit. [0042] FIG. 6A shows the arrangement of the recovery units placed in an extraction unit. [0043] FIG. 6B shows the arrangement of the recovery units after the lid is compressed. Detailed Description Of The Preferred Embodiments [0044] One embodiment of a deformable sealing compound sheet ("sealing sheet") is shown in FIG. 1. This embodiment of a sealing sheet comprises: a composite plastic sheet 20, a deformable cavity 40 in the composite plastic sheet, a top portion 60 of the sheet 20, a bottom portion 50 of the sheet 20, and a carrier frame 30 to which the sheet 20 is attached. The composite plastic sheet 20 in this embodiment is capable of creating individual, effectively liquid tight seals, for substantially all deformable cavities 40 in the sheet when the sheet is pressed against a multi-well recovery plate 90, such that the sheet 20 effectively seals each of the wells of the recovery plate 90, as is shown in FIG. 2. With reference to FIG. 1A, the composite plastic sheet 20 is attached to the carrier frame 30, which provides the composite plastic sheet with structural support. The composite plastic sheet 20 comprises three layers, as shown in FIG. IB. There is a bottom layer 21, a middle layer 22, and an upper layer 23, all of which are discussed more fully below. Deformable cavities 40 are pressed into the top 60 of the composite plastic sheet 20, so that the bottom 50 of the composite plastic sheet 20 has protrusions. The compound can be added to the deformable cavities 40 dissolved in DMSO 42. Upon drying of the solvent, the compound remains in the deformable cavity as a dried film 41. Both dissolved 42 and dried 41 compounds can exist on one sheet 10 at the same time; however, this particular combination is merely for exemplary purposes. The sealing sheet 10 can also comprise an identifying marker 70, such as a barcode, by which the sealing sheet can be identified. The sealing sheet can also comprise an orientor 80, by which sequential numbering of the defoonable cavities can identify the cavities. The marker 70 may serve as an orientor as well. [0045] In addition to the sealing sheet, the present embodiments provide for a recovery plate. FIG. 1C and FIG ID show an embodiment of the recovery plate 90. The recovery plate 90 comprises a rigid body 100, which comprises multiple wells 110. The wells 110 are aligned with the deformable cavities 40 of the sealing sheet 10 such that alignment and placement together of the sealing sheet 10 and the recovery plate 90 will result in communication of the deformable cavities 40 and the recovery wells 110. The recovery plate 90 can also comprise a solvent 120, such as DMSO, or a solvent with a dissolved compound 130. The recovery plate 90 can also have a marker 135 that cooesponds to the marker 70 on the sealing sheet 10. Similarly, the recovery plate 90 can comprise an orientor 140. h one embodiment, the recovery plate can be custom made or a standard, commercially available microtiter plate. [0046] The sealing sheet can be used for dry compound storage, and is especially useful for storage and recovery of compounds used in high throughput screens (HTS). With reference to FIG. 1A and IB, in one embodiment, a dissolved compound 42 is placed in a deformable cavity 40 on the sheet 10 and the compound is dried to form a dried compound 41, and is stored. Drying is preferably done under a vacuum or an inert atmosphere, such as nitrogen or argon. The dried compound 41 can be stored in its dry form for long periods without compound degradation, a common problem in storing compounds in liquid form. The compound can be rapidly and accurately recovered by using the sealing sheet as a sealing means for a recovery plate that has solvent in it. [0047] One embodiment of the recovery procedure is depicted in FIG. 2A-2F. Briefly, first, as shown in FIG 2 A, the sealing sheet 10 is placed upside down, on top of the recovery plate 90, which can contain a solvent 130. Once placed on top of the recovery plate, the sealing sheet is flattened, as shown in FIG 2B. The flattening of the sealing sheet acts to create a tighter seal between the sealing sheet 10 and the recovery plate 90. This flattening also results in the deformable cavities 40 being flattened, which aids in accuracy and speed of recovery of the compound. The compound is then dissolved, as shown in FIG. 2C-2F. [0048] In one embodiment, the term "compound" means any substance that can be used on an embodiment of a sealing sheet. In another embodiment, a compound is a substance that can be used with an embodiment of a sealing sheet and a recovery unit. In one embodiment, the substance can be any chemical or biological material, including DNA or samples derived from living organisms. In one embodiment, the compound is usually part of a library of compounds, such as in a combinatorial library. In one embodiment, the term "compound" means any substance that can be dissolved in a solvent and placed onto a deformable cavity of a sealing sheet to be dried. In this embodiment, the dissolved sample can also be dried to create a dried film of the substance on the sealing sheet. In this embodiment, the substance of the dried film can also be dissolved in a solvent by the use of a recovery plate. [0049] The term "deformable cavity" 40 means that there is a three-dimensional structure that is capable of maintaining a liquid compound in a predetermined location until it is dried. In one embodiment, the cavity is an impression on the sealing sheet that serves to stabilize a drop of dissolved compound, hi a prefeoed embodiment, the cavity is an impression in the sheet in which the droplet of dissolved compound 42 is dried to create the dried compound 41. One preferred embodiment can be seen in FIG. 4A and FIG. 4B. In still another embodiment, droplets of dissolved compound are maintained on the sealing sheet 10 by other means, such as by defining the defoonable cavity 40 by surrounding a first zone of the sealing sheet with a second zone, with or without indentation, wherein the zones are formed of materials to contain and maintain liquid droplets in a desired location. Thus, as shown in FIG. 4C and FIG. 4 D, the first zone 46 can have an affinity for the liquid of the droplet, and the second zone 45 can repel the liquid of the droplet, such as (for an aqueous solvent) a hydrophilic-hydrophobic interaction. In some embodiments, only one zone is required. These zones can be formed on the sheets in a variety of ways. For example, the zones could be applied through a rotogravure process where the different zones are applied in separate printing passes. Another example is to use an ink jet printer type process. The desired designs of the zones are created in a file to output to a printer and there are various cartridges in the printer, the cartridges containing the materials for designing the various zones. [0050] In a more preferred embodiment, the deformable cavities 40 are those created as described below, as shown in FIG. 5. In one embodiment, the composite plastic sheet 20 of the deformable cavity 40 protects the compound from gases or radiation, or other substances that might damage the compound while the compound is still solvated. Of course, as is appreciated by one of skill in the art, this protection can be limited since the top surface of the sample is not necessarily directly protected by the sealing sheet. However, placing the sealing sheet upside down will allow the sealing sheet to provide further protection of the samples from some of the particulate matter in the atmosphere. Furthermore, stacking the sealing sheets together can also provide additional protection for dried samples. For instance, one can effectively seal a sample within a deformable cavity of a first sealing sheet by using, as a lid, the bottom of a deformable cavity of a second sealing sheet that is placed on top of the first sealing sheet. In such an arrangement, both space saving and sample stability and purity will be improved. With sensitive compounds, it is advantageous to initially dry them under a nonreactive atmosphere or under a vacuum. [0051] By "deformable" cavities 40, what is meant is that the three dimensional shape of a cavity can be changed or even eliminated, e.g., through flattening. In one embodiment, the usefulness involves creating an effectively solvent-tight seal, thus keeping the compounds 41 from mixing with each other. As will be understood by one of skill in the art, this separation need not be absolute. In some situations, tiny amounts of mixing of compounds may not alter the results or there may be other steps with larger amounts of contamination, making minor cross contamination at this step largely irrelevant. In one embodiment, the change in the three dimensional structure of the defoonable cavity 40 should also be achieved without a significant loss in compound 41, 42, and/or 130. Compound loss can occur for many reasons, for example, if the composite plastic sheet 20 is ruptured or if the recovery plate 90 breaks, hi a more preferred embodiment, the ability of the deformable cavity to change its three dimensional shape is substantial enough so that once compressed, it results in a breaking up of the compound 41. In one embodiment, the compound is in the form of a dried film 41 on the surface of the sheet 10 in the deformable cavity 40. In one embodiment, the deformation 155 of the cavity is such that it alters the interior surface of the defoonable cavity 40, thus allowing the compound to be broken up, as shown, for example in FIG 2B. This breaking up of the compound 41 allows for a much larger surface area of the compound to be exposed to solvent, for instance, the entire side of the film making up the dried compound 41 that abuts the surface of the defoonable cavity 40. The detachment of the film from the wall of the deformable cavity also exposes the compound to a larger range of motion from techniques such as shaking and centrifuging, thus increasing the chance of solvation. Additionally, by flattening the deformable cavity, one has greatly increased the chance that the compound has been broken up into multiple pieces and is within the solvent. Additionally, the more numerous the pieces of compound, the greater the surface area, and the greater the chance that during agitation, one piece will hit another resulting in further compound breakup and solvation. Without this compression, the compound may not break away from the composite plastic sheet 20 and may not readily or completely dissolve. Additionally, the tight fit between the sealing sheet and the recovery plate helps prevent cross contamination and loss of the solvent. [0052] In one embodiment, the deformable cavities 40 can be compressed, while the sealing sheet 10 is on a recovery plate 90. In a preferred embodiment, the deformable cavities 40 can be compressed without the sheet losing its effective sealing capabilities. In other words, the compression of the deformable cavities does not disturb the seal between the sealing sheet and the recovery plate. By "disturb" what is meant is that the seal is broken to the point of not being useable for its intended use. As will be appreciated by one of skill in the art, a perfect seal is not required for many applications; thus, a small amount of cross contamination between compounds may be tolerated in some applications, but might be impeonissible in others. [0053] In one embodiment, the defoonable cavities are deformed from a planar state. In other words, if the three dimensional surface of a defoonable cavity is planar, such as shown in FIG. 4D, then the deformation will result in the planar sheet being altered. One method of preparing such planar defoonable cavities is by placing various bands of hydrophilic and hydrophobic regions on the sheet, as depicted in FIGS. 4C and 4D. h one embodiment, the various bands could be "printed" onto the sheets in the manner depicted in FIG. 4C and 4D. As discussed above, one region can be a hydrophilic region, and the other a hydrophobic region. As appreciated by one of skill in the art, exactly how this is this arranged can vary according to the particular application. There are many ways the deformation itself could be achieved. In one embodiment, the reverse stamp 180 of FIG. 5 is used to defoon the defoonable cavities. In this embodiment, the process would be similar to that shown in FIG. 5. In FIG. 5 A the reverse stamp 180 would depict a "lid" similar to the lid 150 as in FIG. 2, instead of simply a reverse stamp. The sealing sheet 11 is aligned underneath the reverse stamp or lid 180 so that the nodules 185 of the lid are aligned with the effective compound of the deformable cavity 46. The nodules 185 are then lowered through the plane of the sealing sheet 11, as shown in FIG. 5B, thus deforming the compound cavities. The reverse stamp or lid 180 can then be removed and the sealing sheet processed as shown in FIG. 2. In another embodiment, the protocol is identical to that shown in FIG. 2 and explained below, except that the lid 180 is used instead of the lid 150. [0054] In one embodiment, the sealing sheet 10 comprises a composite plastic sheet 20. In a more preferred embodiment, the composite plastic sheet 20 comprises a layer of a plastic-like material 21, a layer of metal 22, and a layer of plastic-like material 23. In a more prefeoed embodiment, the layer of metal is located between the two layers of plastic. Without intending to be limited by theory, the inventors hypothesize that the layers of plastic provide both structural and protective features. One structural feature that the plastic provides to the sheet is that it allows the sheet to maintain a shape and allows deformation of the shape while maintaining the integrity of the seal. One protective feature is that the plastic provides a known substrate upon which a compound can sit without great risk of contamination. The metal provides both structural features, such as giving the sheet the benefits of aluminum in maintaining a shape but allowing deformation, and in some embodiments, a protective feature, as a barrier, protecting the compound from light and gases that might permeate the plastic layers. When the sheet 10 is sealed to a recovery plate, the barrier properties of both the plastic and the metal prevent oxygen or other potentially deleterious gases from entering, and prevent solvent from leaving the wells of the plate. [0055] In one embodiment, the layers of plastic making up the sheet 10 can be comprised of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polytetrafluoroethylene (PTFE), or other plastic like materials. In one embodiment, the metal 22 is comprised of aluminum. In a preferred embodiment, the composite plastic sheet 20 is comprised of a layer of polyethylene, a layer of aluminum, and a layer of polyethylene terephthalate (PE/A1/PET). hi another embodiment, the composite plastic sheet is comprised of PET/A1/PET. In another embodiment, the composite plastic sheet is composed of PS/A1/PP. In another embodiment, the composite plastic sheet is comprised of PS/A1 PE. In one prefeoed embodiment, the composite plastic sheet is NTT Exportfoil E-100 [trade] from NTT AG (distributor, Switzerland, Reinuch). The VTT Exportfoil E-100 sheet comprises a 19 micrometer layer of PET, a 15 micrometer layer of Al, and a 100 micrometer layer of PE. As will be appreciated by one of skill in the art, many variations of plastics and metals are possible without leaving the scope of the present embodiments. Additionally, as will be appreciated by one of skill in the art, the thickness is not necessarily the ultimate guiding factor, rather, stability, deformability, and inertness of the deformable sealing compound sheets are the main factors in considering whether or not the material or combination of materials is useful as a defoonable sealing compound sheet. [0056] In one embodiment, the layers are chosen on the following general properties. The top layer performs a sealing function and a compound storage function. When the sheet is pressed or placed against a recovery plate, the top layer preferably forms an effectively liquid tight seal and can foon an effectively vapor tight seal. By "sealing" it is meant that the layer helps to foon a seal, as one might use a rubber washer or a gasket to help create a seal between two objects. Additionally, a seal should be maintained even after the defoonable cavities are deformed. Thus, not only should a seal between the sealing sheet and the recovery plate be maintained, but the integrity of the defoonable cavity should be maintained so that no significant amount of solvent or sample is lost. The term "sealing," by itself, is not meant to suggest that there is a durable adhesive property to the sealing layer, as may be present in adhesive seals such as glue seals or heat seals, h an alternative embodiment, such adhesive sealing layers could be incorporated into the sheets or replace the sealing layer described above; however, such seals are explicitly defined as "adhesive seals" rather than simply "seals." The top layer should also be relatively inert to the sample and the solvent, assuming inertness is desirable. The top layer also helps to provide mechanical structural support. [0057] The middle layer should provide defoonability benefits and optionally barrier properties. The bottom layer should provide additional structural support, both for the actual shape of the deformable cavity, and for the deformation of the sample during recovery. Additionally, in some embodiments the bottom layer can be useful for the addition of the caoϊer frame. In some embodiments, the combination of the layers results in a sealing sheet with the following known properties: mechanically and chemically stable, weldable, deformable, and sealable. [0058] As will be appreciated by one of skill in the art, in some embodiments, not all of the layers need to be used to create a deformable sealing compound sheet, h one embodiment, only the material of the middle layer 22 is used and the outer layers 23 and 21 are not present as part of the sheet. In such an embodiment, the material should still be able to foon a seal with the individual wells of the recovery plate and be structurally stable. Additionally, in such an embodiment, the material preferably should not react with the compounds or solvents. Finally, the material should be deformable. However, as is appreciated by one of skill in the art, it may be difficult to achieve this in some situations, especially when the compound is dried which may result in the atmosphere around the sealing sheet becoming very cooosive. In such situations, it may be necessary to use more than just a single layer and to protect the middle layer with the above described layers. An additional issue that arises with just a single layer is mechanical stability of the cavity and sheet, which also should be sufficiently high to allow use of the sealing sheet as described herein. [0059] In an alternative embodiment, only the material of layer 23 or 21 is used as the material for the deformable sealing compound sheet, although the same general principles described above still apply, an alternative embodiment, two of the three layers are used, either two plastic type layers, or a plastic type layer and a metal type layer. While defoonable sealing compound sheets comprising only a subset of the three layers may not have all of the advantages of the sheets with all three layers, as appreciated by one of skill in the art, there may be situations where a single or double layer sheet is sufficient. Additionally, in certain circumstances, for instance when the solvent and compounds used are inert to the material of layer 22, it may be advantageous for the deformable sealing compound sheet to consist of only layer 22, or layer 22 and layer 21, as this can reduce the possibility of the solvent or compound reacting with the plastic like layer 23. [0060] In one embodiment, the sealing sheet 10 comprises a caoier frame 30. A caoier frame can provide structural support for the plastic sheet, or foil, of the sealing sheet and allows for ease of manipulation of the sheet and thus the compounds, h one embodiment, the carrier frame 30 is similar or identical to the carrier frame in FIG. 3. The caoier frame 30 can be made from practically any type of rigid material, h one embodiment, the frame is made from either PET or PP-plastic. The general format of the carrier frame is similar to the frame section of a recovery plate. The frame can contain an orientor 170. hi one embodiment, the frame is designed to match up with a multi-well plate, such as a standard microtiter plate. In other words, the carrier frame can help provide a means by which the wells of the recovery plate 90 and the defoonable cavities 40 of the sealing sheet are aligned, hi one embodiment, the caoier frame comprises a frame that also has an additional rigid sheet of plastic across the surface of the frame. Holes are punched into this surface and the sealing sheet is placed on top of the rigid plastic sheet such that the bottoms of the defoonable cavities can stick through the holes on the rigid plastic sheet. The rigid plastic sheet provides additional support for the sealing sheet, while the holes in the rigid plastic sheet are aligned so as not to interfere with the three-dimensional structure of the deformable cavities. The composite plastic sheet 20 can be attached to the carrier frame 30 in any number of ways. The method of attachment is not critical so long as it allows for the use of the sealing sheet 10. h one embodiment, the composite plastic sheet is attached with glue. In one embodiment, the composite plastic sheet is attached via mechanical means. In one embodiment, the composite plastic sheet 20 is attached by welding the sheet 20 to the frame 30. [0061] The deformable cavities 40 of the sealing sheet can be created in any number of ways, hi a preferred embodiment, the deformable cavities are created with a reverse press or stamp that has the inverted shape of a 96 or 384 well microtiter plate. In this embodiment, the composite plastic sheet 20, attached to a caoier frame 30, is situated under a press or stamp device 180, as shown in FIG. 5A-C. The stamp is first positioned above the sealing sheet, as shown in FIG. 5 A. The stamp contains at least one nodule 185, so that pressing the stamp into the plane of the sealing sheet, as shown in FIG. 5B, results in a defoonable cavity 40 that is complementary to the nodule 185, as shown in FIG. 5C. Thus, by selecting the size of the nodule and the depth of pressing the nodule into the composite plastic sheet, one can select the size of the defoonable cavity. In one embodiment, a one-microliter cavity is the size of the desired cavity. Additionally, by altering the number and arrangement of the nodules, one may alter the number and positioning of the deformable cavities and thus the appropriate type of recovery plate used in conjunction with the sealing sheet can also be altered. In one embodiment, a 96 well plate is the arrangement of the nodules. In one embodiment, a 384 well microtiter plate is the aoangement of the nodules, hi another embodiment, a 1536 well microtiter plate is the aoangement of the nodules, hi one embodiment, the actual stamping process itself helps to enhance the defoonability of the defoonable cavities. Without intending to be limited by theory, it may be that the stress caused to the sheet during the stamping process helps to alter the deformability characteristics of the stamped area, thus enhancing the defoonation abilities of the defoonable cavities during recovery. [0062] In the practice of the invention, the end user in one embodiment will actually create the sealing sheet 10 having defoonable cavities 40 using a machine or system located on-site. hi another embodiment, sheets having deformable cavities will be provided in a pre-made state, and the end user can then place and dry any desired materials on the sheet, hi still another embodiment, a first party can create sheets having standard or custom libraries of compounds dried thereon, optionally sealing the sheets with a barrier material to be removed by an end user, and can then provide those sheets and libraries of compounds or other materials to an end user. Alternatively, the sheets can optionally be packed into a container, a bag for example, and sealed under an inert atmosphere. Again, these sheets can then be provided to an end user. [0063] As shown in FIGS. 1C and ID, a "recovery" plate 90 is a relatively rigid plate containing wells for a solvent 120. The recovery plate is rigid relative to the sealing sheet. The recovery plate is able to maintain, throughout the recovery process, a well 110 that is effective in holding a solvent. The recovery plate must also have an effectively rigid body 100 against which the sealing sheet 10 can be pressed and be sealed. The size, number, and arrangement of the wells 110 in the recovery plate can be varied to any practical degree. The primary limitation being that at least one of the deformable cavities 40 on the sealing sheet should be able to effectively interact with at least one of the wells on the recovery plate. In one embodiment, the recovery plate is a multi-well plate. In one embodiment, the recovery plate is a 96 well microtiter plate. In one embodiment, the recovery plate is a 96 well or 384 well microtiter plate, hi one embodiment, the recovery plate is a 1536 well microtiter plate. Both custom and standard, off-the-shelf recovery plates can be used in the present invention. [0064] As shown in FIG. 2B, a sealed recovery unit 160 comprises a sealing sheet 10 and a recovery plate 90. The deformable cavities 40 on the sealing sheet are able to communicate with the wells on the recovery plate 110 when a sealed recovery unit 160 is created. Additionally, the sealed recovery unit seals a defoonable cavity and a well on the plate. "Seal" is meant as a relative teon, and not an absolute teon. Thus, in one embodiment, the placement of a sealing sheet over a recovery plate with solvent in the recovery plate, so that the solvent and solvent vapor is effectively concentrated within the well and the deformable cavity, will result in a sealed recovery unit. In one embodiment, a sealed recovery unit 160 is formed when the sealing sheet 10 is pressed against the recovery plate 90 with enough force that the liquid solvent 120 is effectively contained within the area bounded by the interior of the well of the recovery plate and the top 60 of the sealing sheet. In one embodiment, the sealed recovery unit can refer to a single well 110 and defoonable cavity 40 or defooned cavity 155. In another one embodiment, the sealed recovery unit can refer to the entire recovery plate being sealed by the sealing sheet and all the sealed individual wells collectively. As will be understood by one of skill in the art, not every well and cavity need be sealed. Additionally, as disclosed above, each seal can be but is not necessarily absolute. [0065] hi one embodiment, multiple sealing sheets are stored together to create a larger library of compounds. This allows for large numbers of compounds to be available for HTS. In one embodiment, the sealing sheets are cataloged and possibly arranged by the marker 70 on each sealing sheet. In one embodiment, the location of each sealing sheet is maintained in a database to allow for quick recovery on the sample. In another embodiment, the database contains the identity of each compound on each sealing sheet and the location of each compound with respect to the compound's location on the sealing sheet and the location of the sealing sheet in the library. [0066] Because the compounds are dry, the manner in which the sealing sheets are stored in the library is not as critical as it normally would be. Indeed, it is partially because these compounds can be stored in a dried format on these sheets, that one reduces the large amount of equipment and space that is usually necessary for storing libraries of compounds. Thus, the libraries of these sealing sheets are more cost and space efficient than traditional libraries that use dissolved compounds that must be maintained in a particular atmosphere. Of course, the libraries of the current embodiment can also contain a particular atmosphere, or employ robotics for retrieval of sealing sheets and dissolving compounds. However, the libraries of the present embodiment still enjoy a higher degree of compound stability than traditional libraries do, and, through the use of the recovery unit, are able to simultaneously recover and present numerous compounds. In one embodiment, once the compounds are substantially dried, the sealing sheets are turned upside down and stacked, either simply on top of one another or in a shelve system to allow ease of access to individual sealing sheets. Additionally, while not required, the sealing sheets themselves can be sealed to add to the stability of the sample. There are many methods by which the sealing sheets can be sealed. In one embodiment, a foil is placed on the top of the sealing sheet. In another embodiment a plastic is used, hi another embodiment, a composite plastic sheet is used to seal the sealing sheet. In another embodiment, a sealing sheet is used to seal another sealing sheet. In another embodiment, a recovery plate is used. Each of these additional means for protecting the sealing sheet is optional. Alternatively, the individual sheets need not be individually sealed, but rather may be placed into a container that contains a controlled atmosphere. [0067] In one embodiment, the method of using the defoonable sealing compound sheets comprises loading a liquid compound onto at least one defoonable cavity, drying the compound, storing the sheet, recovering the sheet, redissolving the compound, and collecting the compound. [0068] As will be appreciated by one of skill in the art, loading a liquid compound can be achieved in any number of ways, hi one embodiment, the compound is pipetted by hand onto the deformable cavity. In another embodiment, the compound is loaded onto the sheets by a robot or other form of automated pipetting. Any solvent can be used, so long as it does not detrimentally interact with the sealing sheet. While an aqueous solvent can be used in certain circumstances, in a preferred embodiment, dimethyl sulfoxide (DMSO) is the solvent used. The volume of the compound added is only limited by the holding capacity of the deformable cavities, including surface tension effects that may allow a droplet to extend above the sheet 10 while still maintaining a predefined location thereon. In one embodiment, one microliter volumes of compounds are used in one microliter deformable cavities. As will be appreciated by one of skill in the art, larger volumes of compound can be used while still using the same size of deformable cavities. In one embodiment, the volume of dissolved compound used is from 0.1 to 1.0 microliters. The primary factor in compound size being that the compounds, when dried, are contained within the area around the deformable cavity 40 that will be effectively within the well 110 of the recovery plate 90 when the sealing sheet and recovery plate are placed together to form the recovery unit 160. Additionally, the amount of compound in a particular deformable cavity can be increased by repeated rounds of application of the dissolved compound followed by evaporation of the solvent. [0069] In one embodiment, a tracer or marker 70 is associated with the sealing sheet when the compound is added to the sheet, to allow one to identify particular compounds on the sheet. The marker can be any means to identify the sheet and can be machine readable. The marker can be a one-dimensional or two-dimensional marker, such as a symbol or barcode. The marker can be a three-dimensional marker; for instance, it can be pressed into the sheet or the carrier frame that holds the sheet. Alternatively, the marker can be a radio frequency tag ("RF tag"). In one embodiment, the marker or label is located at a predetermined location on the sheet, so that the orientation of the plate allows one to know the identity of the compound in each deformable cavity. In another embodiment, the marker itself provides the orientation of the plate with which one can then identify compounds of each of the defoonable cavities. For instance, if there are 96 deformable cavities and the marker 70 is always in the upper right hand comer of the sealing sheet 10, then one can number the defoonable cavities to identify the compound by its deformable cavity number. One option is to simply start numbering the defoonable cavities in the upper left cooler of the sealing sheet and go across to the right side, each row at a time; thus creating a series of sealing sheets with an identical numbering system. Because of the location of the marker, and the system of numbering, individual numbers need not be labeled on the sealing sheet. Similarly, a marker 135 can be placed and used on the recovery plate. It is important to note that the transfer from the sealing sheet to the recovery plate results in a mioored arrangement of compounds, and not an identical aoangement of compounds and so the numbering for the identification of the compounds should be adjusted accordingly when the compounds are transferred. In one embodiment, the marker is put on the carrier frame. In an alternative embodiment, each cavity is identified with a marker. The manner in which each compound or sealing sheet is labeled will depend on the intended end use of the sealing sheet. [0070] As will be appreciated by one of skill in the art, drying the compound can be achieved in any number of ways, hi one embodiment, the compounds are simply left to air dry. In another embodiment, the sheets are placed in a container that contains an inert atmosphere, such as nitrogen or argon. In a preferred embodiment, the container works with a small excess pressure of the inert gas, thus resulting in a steady stream of gas from the inner part of the container to the outer atmosphere. This allows the solvent to be removed more quickly and still prevents oxygen and water from reaching the interior of the compartment when the compound is still dissolved in DMSO. As will be appreciated by one of skill in the art, the more of the solvent that is removed, the more stable the compound will be. hi one prefeoed embodiment, the solvent is removed under vacuum. However, there may be situations in which complete removal of the solvent or all solvents is not necessary or desirable, as it may result in greater difficulty redissolving the compound later, hi one embodiment, the sheet is labeled with an identifying marker 70. The marker can be attached before a compound is added to the sheet. In such an embodiment, pre-labeling the sheets allows one to simply compare a source compound plate and the sheet, which may occur at anytime, preferably during or after pipetting. In another embodiment, the marker is added after the compound is dried. [0071] The sealing sheets can be stored under any number of conditions, hi one embodiment, the sheets are kept in the normal atmospheric environment. In a preferred embodiment, these sheets are placed upside down, in order to prevent airborne contaminants from contaminating the deformable cavities. In one embodiment, the sheets are stored under nitrogen, to further add to the stability of the compounds contained thereon and to avoid contaminants. Alternatively, the sheets can be enclosed in a container having a controlled atmosphere, or the sheets can have a removable layer attached over the cavities 40 to seal them and protect them from the ambient environment. This removable layer can be a material having high vapor baoϊer properties, such as a metallized PTFE material or a composite plastic material such as the material from which the sheet 10 is formed. In one embodiment, the sheets are stored in a library of sheets in order to be used for high throughput screening. In one embodiment, the storage is automated by machines. [0072] The sealing sheets can be retrieved in any number of ways. In one embodiment, the location of the sealing sheet is recorded in a database and one can simply use the marker 70 to locate the sealing sheet, h another embodiment, the sealing sheet is stored according to its marker and thus knowing the marker lets one know the location as well. In one embodiment, retrieval can be completely automated, as in many arrangements for high throughput screening. Additionally, although the compounds are located on a composite plastic sheet, the entire sheet need not be redissolved in order to recover the compound. In one embodiment, only a subset of the compounds on the defoonable cavities is recovered. For example, the entire sheet can be recovered, but only the selected cavities will be processed, as described below, h one embodiment, this can be achieved by only placing solvent 120 in a subset of the wells of the recovery plate 90. In another embodiment, this is done by pressing, and thus sealing, only a section of the sealing sheet against the recovery plate for the procedures described below. In another embodiment, the defoonable cavities 40 containing the compound 41 can be cut or stamped out of the sealing sheet 10 and further individually processed as described below, or simply recovered by soaking the isolated defoonable cavity in solvent. Cheoy picking allows for a more efficient use of the compounds. [0073] The compound may be redissolved by any number of solvents. As will be appreciated by one of skill in the art, any solvent may be used, so long as it does not detrimentally interact with the sealing sheet or the recovery plate, hi one embodiment, DMSO is used, hi alternative embodiments, the solvent can be methanol, tetrahydrofuran (THF), acetonitril, water, other organic solvents, and solvent mixtures, hi some embodiments, especially when hydrophobic compounds are used, solubilization enhancers could be added to allow for better recovery with hydrophilic solvents, such as water. [0074] One embodiment for the solvation of a compound is shown in FIG 2. The dried compound 41 is recovered from the sealing sheet 10 by placing the sealing sheet against a recovery plate 90 containing a solvent 120. As shown in FIG. 2A, the sealing sheet 10 is first aligned with the recovery plate 90. Next, the sealing sheet 10 pressed against the recovery unit 90. The wells 110 of the recovery plate 90 are in communication with the deformable cavities 40 of the sealing sheet 10. This creates a recovery unit 160 with respect to the solvent vapor. Next, as shown in FIG 2B, the sealing sheet 10 is pressed against the recovery plate 90 creating an effective liquid tight seal between each deformable cavity 40 and each well 110 of the recovery plate 90. This combination results in the creation of a recovery unit 160. This can be achieved by the use of a lid 150. The lid can be a single planar piece of effectively rigid material, as shown in 150. In other embodiments, it can contain additional structures, such as one embodiment of lid 180. Alternatively, it can comprise alteo ative or additional elements, as discussed further below. The pressure of the lid 150 against the rigid body 100 of the recovery plate 90 and the sealing sheet 10 results in the effective liquid tight seal. Additionally, the lid 150 also performs the function of deforming the deformable cavities 40. The compression of the defoonable cavities results in deformed cavities 155. As appreciated by one of skill in the art, defoonable cavities without compounds need not be sealed. As discussed above, the seals need not be perfect in every application, but only sufficient for the purpose of recovering the compound for a particular intended end use. The deformation 155 of the defoonable cavities 40 promotes the complete solvation of the compound in the defoonable cavity. In one embodiment, all of the defoonable cavities 40 can be compressed at once by using a lid 150, as shown in FIG. 2. The lid 150 can be attached in any suitable manner, such as using clips or clamps, or by placing the entire recovery unit 160 in a frame or press, such as an extraction unit. It will also be appreciated that the recovery plate 90 or the sheet 10 can be provided with a suitable solvent-resistant adhesive, so that upon mating the two objects together, the adhesive will retain them together and seal the sheet 10 to the plate 90. [0075] Following this compression, the solvation can be enhanced further by any number of methods to facilitate recovery of compound. In one embodiment, shown in FIG. 2C, the recovery unit 160 is turned upside down to bring the solvent 120 in direct contact with the dried compound 41 in the deformable cavities 155. As shown in FIG 2D, the recovery unit 160 is shaken to dissolve the compounds. The dried film of the compound 41 will be returned to solution 130. As shown in FIG 2E the recovery unit 160 is then turned right side up. As shown in FIG. 2E the recovery unit 160 is centrifuged to return the dissolved compound 130 to the bottom of the recovery plate wells 110. Finally, as shown in FIG. 2F, the lid 150 and the sealing sheet 10 are removed and the compound 130 remains in the recovery plate wells 110, in solubilized foon 130. As will be appreciated by one of skill in the art, the exact technique employed to assist in dissolving the compound can be varied without impacting the present embodiments. For instance, in situations where heating the compounds is not detrimental to the compound, it may be desirable to apply heat to the plates in order to promote solvation. Alternatively, instead of relatively large shaking motions, ultrasound can be employed to assist in the solvation of the compound. Alternatively, while cooling the plates may not directly help in dissolving the compounds, it can add to compound integrity and thus be beneficial to the overall solvation process. [0076] hi one embodiment, compression and manipulation of the recovery unit is achieved with an extraction unit. In one embodiment, the extraction unit aligns the sealing sheet 10 and the recovery plate 90 so that the wells 110 and the defoonable cavities 40 are in communication with each other. The extraction unit can also help to level the top of the recovery plate with the top surface 60 of the sealing sheet 10. This allows for a tight seal between the wells 110 and the defoonable cavities 40. The extraction unit can also compress the defoonable cavities. The extraction unit may fit onto commercial available centrifuges and shakers. The extraction unit may readily and rapidly be opened and closed. If there are multiple recovery units, the extraction unit may apply pressure evenly to the entire series of recovery units. [0077] One embodiment of an extraction unit 215 is represented in FIGS. 6 A and 6B. In this embodiment, the extraction unit comprises an extraction plate 216 upon which a recovery plate can be positioned, thus being aligned and oriented in a precise manner. Alternatively, the recovery plates can simply be placed in the base of the extraction unit 215. The extraction unit can also comprise a lid 150, which can also serve as the extraction plate for the next recovery plate. A sealing sheet 10 and a recovery plate 90 are placed on top of each other and a lid 150 is placed on top of the recovery unit, hi one embodiment, the lid comprises two different elements, a softer rubber-like substance 155 that helps to make sure that the pressure exerted by the extraction unit is evenly distributed over the surface of the sealing sheet, and a rigid material 156, that is capable of withstanding the high pressure applied to the surface and distributes pressure, which can be applied at a point on the surface of the cover-lid 210, over a larger surface area. The lid 150 can also consist of just one of two elements. In one embodiment, the lid 150 consists of a soft substance and the bottom of the recovery plate 90 of the plate above the recovery unit can act as a rigid material. Likewise, as will be appreciated by one of skill in the art, if the alignment and placement of the recovery units and plates are precise enough, the need for the soft material decreases. A cover-lid 210 can be used on the top of the extraction unit. The closeness of the fit between the cover-lid 210 and the body of the extraction unit 215 can provide additional precision, accuracy, and stability to the arrangement. As appreciated by one of skill in the art, in some embodiments, the lids 210 and 150 could be used interchangeably. However, the cover-lid 210 can have some advantageous design features for directly receiving the compressive force and the lid 150 can have some design features for receiving a recovery unit on top of it. In one embodiment, the advantageous design elements of the cover-lid 210 and lid 150 are combined into a single lid, thus allowing a single lid to function for all uses. [0078] In one embodiment, several of the recovery units and lids can be placed within the body of the extraction unit 215, for example, as shown in FIG. 6 A. The extraction unit can optionally comprise additional elements to assist in further processing of the samples. FIG. 6A displays an extraction unit with a holder 200 for positioning the extraction unit into a centrifuge without a beaker or holder and a positioning tool 205 to allow for placing the extraction unit into a beaker or holder. Both parts need not be included on the same device and the absence of the positioning tool 205, can allow for an additional recovery unit to be placed into the extraction unit. Of course, as appreciated by one of skill in the art, other elements can be added or removed as needed. Next, a cover-lid 210 is placed on top of the stack of lids, plates, and sheets, as shown in FIG. 6 A. This cover-lid 210 is also made from a rigid material that readily transmits the force applied from above to the entire surface area beneath the cover-lid 210. Finally, pressure is applied to the top of the stack to compress and seal the sealing sheets to the recovery plates, as shown in FIG 6B. [0079] In one embodiment, the aoangement of the sealing sheet 10 and the recovery plate 90, before the deformable cavities 40 are compressed, is maintained in order to allow the vapor of the solvent to begin the process of dissolving the compound in the deformable cavities. In an alternative embodiment, the aoangement of the sealing sheet against the recovery plate 90, after they are pressed together, as shown in FIG. 2B, is maintained in order to allow the vapor of the solvent to begin the process of dissolving the compound in the deformable cavities. [0080] h one embodiment, multiple sealed recovery units are processed at the same time. This can be achieved simply by stacking one recovery unit 160 on top of another recovery unit 160 and compressing the entire stack; thus, all the recovery units will become sealed recovery units, hi this manner, one is able to dissolve larger numbers of compounds simultaneously. In one embodiment, an extraction unit is set up to handle multiple recovery units. [0081] In one embodiment, multiple rounds of solvation of a compound can occur in a single recovery plate 90. In other words, one uses a first sealing sheet 10 and a recovery plate 90, as described above, to redissolve the compounds into a solvent 130, in the recovery plate. Then, one can take a second sealing sheet and repeat the process but this time the same solvent from the first recovery plate 130, is used to dissolve the next dried compound. By doing this, one is able to increase the concentration of the compounds redissolved. Additionally, one is able to mix various compounds. These mixed compounds can also be stored on sealing sheets to increase the complexity of a library. The ability to vary the concentration of the dissolved compound in a precise manner is very useful in creating a series of dissolved compounds that can be used to generate a dose response curve for a particular compound. A dose response curve allows one to begin to understand the effectiveness of a particular compound. By being able to create large numbers of these dose response curves simultaneously, one is able to achieve a much more thorough understanding of the compounds' chance of becoming a future drug. Another reason one might want to increase the concentration of a compound is to verify that the original compound may have tested positive or negative, that is, as a verification step. The embodiments described are especially useful in allowing verification of a compound. One can either, rapidly redissolve a plate with a potential lead chemical, or simply cut out the deformable cavity with the potential lead chemical and verify it separately. [0082] The present embodiment can also be used with sealing sheets 10 that are relatively planar; i.e., that do not have physically-formed cavities, but that do have dried compound stored thereon in discrete locations that will line up with a multi-well recovery plate 90. Although the steps that involve defooning the cavity may not be applicable to some of these embodiments, such sealing sheets 10 can nevertheless be aoanged in a sealing relationship over the top of the recovery plate 90 so that solvent in wells of the recovery plate can be used to solvate and recover the dried compound on the sheet 10. [0083] As will be appreciated by one of skill in the art, the dissolved compound 130 can be collected in a variety of ways, hi one embodiment, the sealing sheet is entirely removed from the recovery plate and the compound is pipetted out of the well. In one embodiment, the sealing sheet is left covering the wells of the recovery plate and a needle or similar device is used to penetrate the sealing sheet. The needle or similar device can then be used to withdraw a compound from the recovery plate without exposing the other dissolved compounds to the atmosphere of the room. In another embodiment, the compounds are transferred directly or through the use of an intermediary device, such as a robotic sampler or a spotter, onto another substrate, such as a gel or blotting paper, which can absorb the compounds. Alternatively, the compounds can be transfeored using manual or automated apparatus into any system, substrate, or device capable of participating in or performing an assay. [0084] There are many ways in which certain embodiments of the sealing sheet are advantageous over traditional devices and procedures for maintaining libraries. The following are just a few such examples of the advantages for some of the embodiments of the sealing sheets. [0085] For example, when using a sealing sheet, if one had 300 microliters of stock solution, one could prepare 200 individual wells of compound, each of 1 microliter, each in its own deformable cavity, and additionally prepare 100 microliters of dry backup copies. Each of the wells of compound can be used individually and stored at little expense in either money or space. If one were to perform 20 screens per year and 1 sheet per screen, these sealing sheets would last for almost 10 years, hi contrast, in conventional storage procedures, one would make 10 plates, with 30 microliters per plate, from the same 300 microliters of stock solution. However, in the conventional situation since the samples are kept in a dissolved foonat, the plates must be replaced every half-year. Thus, the compound will only last 5 years. [0086] Another advantage is that the use of conventional plates can result in approximately 8-10 times more space being used than as outlined for the cuoent embodiment of the deformable sealing compound sheets. A standard 384 well plate is approximately 15 mm in height, while the sealing sheets described herein can readily be made to be approximately 1.5 mm in height. Thus, ten times more of the sealing sheets may be stored in the same volume of space as for the standard 384 well plates. [0087] Another advantage is that the use of the sealing sheets allows one to save approximately 30% to 50% of the sample during recovery. If one were to place a larger volume of sample into the above described standard plates the ability to recover such volumes would decrease since standard recovery techniques only allow 5-7 microliter recovery of a 10 micro liter volume. On the other hand, the sealing sheets and recovery techniques described in the present embodiments can allow for effectively complete recovery since one may add the test compound to the sealing sheet. [0088] It is clear that the embodiments provide a substantial advantage over the cuoent techniques. [0089] The embodiments are further illustrated by the following non-limiting examples. Example 1 Use of Sealing Sheets in High Throughput Screens [0090] One microliter of each compound solution is pipetted into the deformable cavities by means of a commercially available pipettor. The solutions are dried down in a special container under an inert and dry atmosphere without centrifugation or the application of a vacuum. The dry sealing sheets are thereafter stored at room temperature. The sealing sheets of interest are withdrawn from storage. One microliter of DMSO is pipetted into each well of a bar coded 384 well microtiter plate and the sealing sheet is laid on top of this plate as a "lid," exposing the dried compound to the vapor of solvent and thus forming a recovery unit. Multiple sets of such recovery units are stacked on one another and the recovery units are all pressed together, with the help of an extraction unit. The bar codes of the sealing sheets and their cooespoiiding recovery plates are recorded. The recovery unit is turned 180 degrees and shaken for approximately 1 to 2 minutes at high rpm. Then the recovery unit is turned back again and centrifuged at 1500 rpm for approximately 1 to 1.5 minutes to ensure that substantially all of the compound solution is contained in the recovery plate. The plate and sealing sheet are released from the extraction umt and the empty sealing sheet from each recovery unit is removed from each recovery plate. Example 2 Time Efficiency of Sealing Sheets in Primary Screens [0091] One surprising result of the current embodiments is that the added time to dissolve a compound, for use in a primary screen, appears to be negligible, rather than the time consuming step that one might normally expect. The recovery of a compound on a sealing sheet involves one retrieving a sealing sheet, labeling a recovery plate, adding solvent to the recovery plate, making a sealed recovery unit, shaking a recovery unit, and centrifuging the recovery unit. All of this takes approximately 10 minutes and results in the creation of an intermediate plate that is then used for the screen. On the other hand, the conventional method involves retrieval of a dilution plate, labeling a secondary plate, centrifuging the dilution plate, desealing the dilution plate, pipetting the compound, washing the tip, sealing the dilution plate, which results in the creation of an intermediate plate which is then used for the screen. All of this also takes approximately 10 minutes. One surprising aspect is that the time involved in using the prefeoed embodiment is approximately the same as that using the traditional techniques, despite the fact that one has to dissolve the compounds each time. Of course, the addition of automated technology could substantially speed up these recovery rates to an even greater extent. [0092] Accordingly, it will be appreciated by those skilled in the art that various omissions, additions and modifications can be made to the products and processes described above without departing from the scope of the invention. All such modifications and changes are intended to fall within the scope of the invention, as defined by the appended claims.

Claims

WHAT IS CLAIMED IS: 1. A recovery unit comprising: a recovery plate having a top and a bottom and a plurality of wells opening at the top of the multi-well plate; and a top sealing sheet, the top sealing sheet having a plurality of deformable cavities, such that a separate deformable cavity is positioned above and in communication with each of said plurality of wells.

2. The product of Claim 1, wherein the top sealing sheet is sealingly affixed to the recovery plate, defining a plurality of sealed chambers, each of said chambers comprising a well of said recovery plate and a deformable cavity.

3. The product of Claim 1, wherein said sealing sheet comprises a second multi-well plate, in which said dry product storage areas comprise wells of said plate.

4. The product of Claim 1, wherein said deformable cavities have been formed by stamping or pressing recesses into a sealing sheet of material.

5. The product of Claim 1, wherein said sealing sheet of material comprises a polymer-foil composite.

6. A method for drying and then dissolving numerous dried materials, said method comprising: a) placing a plurality of wet samples of one or more materials in a plurality of deformable cavities, wherein the defoonable cavities are located in a first sealing sheet in a predetermined spacing; b) drying the wet compounds to create dry compounds on the first sealing sheet; c) storing the first sealing sheet with the dried compounds; d) retrieving the stored first sealing sheet; e) providing a recovery plate having a plurality of wells, wherein said wells are arranged to match said predetermined spacing; f) adding solvent to said wells of the recovery plate; g) matching the first sealing sheet with the recovery plate, such that the deformable cavities of the sealing sheet communicate with wells of the recovery plate; and h) pressing the first sealing sheet to the recovery plate to flatten the defoonable cavities of the sealing sheet, and to foon a sealed recovery unit.

7. The method of Claim 6, wherein the compounds are dried under inert and dry atmosphere.

8. The method of Claim 6, wherein the solvent is a hydrophilic solvent.

9. The method of Claim 6, wherein the solvent is a hydrophobic solvent.

10. The method of Claim 9, wherein the solvent is DMSO.

11. The method of Claim 6, wherein at least one of the first sealing sheet and the recovery plate comprise a machine-readable identifier.

12. The method of Claim 11 , wherein the identifier is a bar code.

13. The method of Claim 6, further comprising stacking several recovery units on top of each other for further processing of all the stacked recovery units simultaneously.

14. The method of Claim 6, wherein the first sealing sheet is sealed to the recovery unit through continuous application of external pressure.

15. The method of Claim 6, further comprising: agitating the recovery unit to dissolve said dry compounds.

16. The method of Claim 15, wherein the agitation comprises the steps of: turning the recovery unit upside down; shaking the recovery unit; turning the recovery unit right side up; and centrifuging the recovery unit.

17. A composite plastic sealing sheet for storing dry compounds, said composite plastic sheet comprising: a layer of metal foil; a coating of plastic on the top of the metal foil; a coating of plastic on the bottom of the metal foil; a plurality of deformable cavities pressed into the sealing sheet in a predeteonined aoangement; and at least one dried compound within a defoonable cavity.

18. The sealing sheet of Claim 17, wherein the sealing sheet is attached to a carrier frame.

19. The sealing sheet of Claim 18, wherein the cavities are about 1 microliter in capacity.

20. The sealing sheet of Claim 18, wherein the cavities are in the orientation of a 96 well microtiter plate, a 384 well microtiter plate, or a 1536 well microtiter plate.

21. The sealing sheet of Claim 19, wherein the coating of plastic on the top of the metal foil is selected from the group consisting of polyethylene, polyethylene terephthalate, and polystyrene, and wherein the metal foil comprises aluminum.

22. The sealing sheet of Claim 19, wherein the coating of plastic on the bottom of the aluminum foil is selected from the group consisting of polyethylene terephthalate, polypropylene, and polyethylene.

23. The sealing sheet of Claim 19, wherein the sheet comprises about 19 μm of polyethylene terephthalate, about 15 μm of aluminum, and about 100 μm of polyethylene.

24. The sealing sheet of Claim 19, wherein the sealing sheet further comprises a machine-readable identifier.

25. The sealing sheet of Claim 24, wherein the machine readable identifier is selected from the group consisting of a 1-D bar-code, a 2-D bar-code, a 3-D bar-code and a radio frequency tag.

26. A library of the sealing sheet of Claim 19 further comprising: more than one sealing sheet, wherein the sealing sheets are positioned in a location that is recorded; and the sealing sheets are stored so that the defoonable cavities are open to the floor.

27. The library of Claim 26, wherein the sealing sheets are stored under an inert atmosphere.

28. The library of Claim 27, wherein the sealing sheets are stored in bags, and wherein the bags contain a relatively inert atmosphere.

29. A method for recovering compounds from a plurality of sealing sheets each having a plurality of compounds dried thereon in a patteoi; comprising: matching each sealing sheet to a plate having a plurality of solvent- containing wells therein such that said wells align with said dried compounds; stacking said plurality of sealing sheets and their associated plates; compressing said stack to seal said sealing sheets to said plates such that said compounds communicate with said wells; and contacting the solvent with said compounds to recover said compounds in liquid form in said wells.

30. The method of Claim 29, wherein the plurality of sealing sheets and their associated plates are stacked within an extraction unit.

31. A method for recovering a plurality of dried compounds from a deformable sealing compound sheet, wherein said compounds are arranged on said deformable sealing compound sheet in a pattern, comprising: sealing said deformable sealing compound sheet to a plate having a plurality of solvent-containing wells therein such that said wells align with said dried compounds; and contacting the solvent with said compounds to recover said compounds in liquid form in said wells.

32. The method of Claim 31, wherein the plate containing the dissolved compound is sealed an additional time with a second deformable sealing compound sheet having a plurality of solvent-containing wells, wherein the dried compound in the first sealing sheet, for a given defoonable cavity, and a dried compound in the second defoonable sealing compound sheet, for a given deformable cavity, are the same type of compound.

33. The method of Claim 31, wherein, following the recovery of the dried compounds into a liquid foon, the plate is used for cheoy picking.

34. The method of Claim 31, wherein following the recovery of the dried compounds into a liquid form, the plate is sealed and stored for verification of hit compounds.

35. A method for solubilizing a library of dried materials, comprising: providing a substrate having a plurality of dried materials thereon in a predeteonined spacing; providing a multi-well plate having wells aoanged in a matching predeteonined spacing and solvent in the wells; matching the substrate to the top of the plate in a sealing arrangement such that individual dried materials on the substrate are matched up with individual wells of the plate; and contacting the solvent in the wells with the materials on the substrate to solubilize the materials into the solvent in the wells.

36. A composite sheet, comprising: a first layer of a polymer material; a second layer of a metal; a plurality of recesses formed in the sheet by punching or pressing; and a plurality of material samples dried in the recesses of the sheet.

37. The sheet of Claim 36, further comprising a web of sealing material applied over the recesses of the sheet.

38. A sheet with deformable cavities comprising: a stable deformable inert sheet; a plurality of defoonable cavities formed in the sheet; a caoier frame that is attached to and supports the sheet; and optionally a plurality of compounds dried in the cavities.