Abstract:
A multi-well plate includes a plurality of wells, and each well has a base and one or more side walls. A liner is located adjacent the base of at least one of the plurality of wells. A method for forming a multi-well plate system includes providing a multi-well plate and applying a liner to a well of the multi-well plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S)  
       [0001]     The present application claims priority to U.S. Provisional Patent App. Ser. No. 60/581,023, entitled “Modified (Glass-Lined) Multi-Well Plates” by Shane J. Stafslien and James Allen Bahr, filed Jun. 18, 2004, which is hereby incorporated by reference in its entirety. 
     
    
     STATEMENT OF GOVERNMENT INTEREST  
       [0002]     The present invention was made, in part, with government finding under the Office of Naval Research (ONR), Grant Nos. N00014-02-1-0794, N00014-03-1-0702 and N00014-04-1-0597. The U.S. Government has certain rights in this invention. 
     
    
     BACKGROUND OF THE INVENTION  
       [0003]     Materials are needed that exhibit antifouling and or easy release properties, for such applications as coatings for naval vessels. It is preferable to use a combinatorial high-throughput workflow when developing such materials. In such combinatorial, high-throughput methods, a need has emerged in the realm of screening and successfully identifying promising candidates from the numerous amounts of materials generated. This need mandates that all valid screening protocols and procedures are rapid, efficient and economically feasible.  
         [0004]     A biological assay is currently being developed and implemented as one such screening protocol to assess the antifouling/foul-release properties of novel coating materials. Coatings are challenged with various marine bacteria and are assessed by their ability to inhibit and or remove bacterial films (biofilms). In this regard, a multiwell plate format amenable to high-throughput methodologies is utilized for the parallel assessment of coatings. However, commercially available formats do not adequately fit the need required for this assay.  
         [0005]     Commercially available plates fabricated from materials such as polystyrene or polycarbonate are not amenable to common coating solvents such as MEK, toluene, acetone etc. Solvents such as these attack the integrity of the plate facilitating a chemical reaction with the plate. This chemical reaction inhibits the formation of a suitable film needed for screening purposes.  
         [0006]     Commercially available multiwell plates fabricated from materials such as glass or polypropylene permit the deposition of common coating solvents. However, these plates are not amenable to high-throughput workflow because the plates are non-disposable, high in cost (ranging in price as high as $400.00-$500.00 per plate) and have the potential to promote delamination of cured coating materials from the wells upon exposure to aqueous environments. Given their high price, glass or polypropylene multiwell plates would require re-use.  
         [0007]     To be able to re-use the plates, the plates would need to be washed or have the coating removed using some similar method. Given that the coatings often cure and harden, removal of the coating from the glass or polypropelyne plate can be difficult. Further, the removal process can etch the glass, or otherwise damage or affect the surface of the plate. Etched or otherwise damaged plates have a negative effect on the high throughput workflow because it may be difficult to apply the coatings as desired to the plates.  
         [0008]     SensoPlate™ glass bottom, black polystyrene, multi well plates are available for purchase from Bellco Glass, Inc. of Vineland, N.J. SensoPlates™ are composed of a high quality optical glass bonded to low auto-fluorescence black polystyrene. The intended applications for this product include high-resolution imaging, sensitive fluorescence and confocal microscopy applications. Though this format could be employed for other high-throughput workflow, several drawbacks or limitations limit its usage.  
         [0009]     SensoPlates™ are expensive (with prices ranging from $39.05 to $222.80 a plate). Once again, the cost of these plates would require their re-use, and the plates are not disposable. The glass bottom is bonded to the polystyrene top. Organic or other common coatings solvents could potentially attack this bond and compromise the integrity of the plate. Depending on the application, other types of material may be advantageous for use as the bottom of each well, (such as metal or plastics, etc.). In this regard, the SensoPlates™ would require further modifications to fit this need.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010]     The present invention comprises a modified multi-well plate, and a method of forming a modified multi-well plate. The multi-well plate comprises a standard multi-well plate, with a non-reactive liner. The inventive plate enables the deposition of a variety of coating formulations (containing common coating solvents) while substantially limiting the solvent interaction with the plate material. Thus, the non-reactive liner minimizes the affect of the solvent on the wells, ensuring abetter deposition, and better test results. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of a polystyrene multi-well plate in which a coating formulation was deposited in the first two rows.  
         [0012]      FIG. 2  is a perspective view of a multi-well plate having an adhesive applied in the bottom of each well.  
         [0013]      FIG. 3  is a top view of one suitable liner for use with the present invention.  
         [0014]      FIG. 4A  is a perspective view of the modified multi-well plate of the present invention.  
         [0015]      FIG. 4B  is a side cross sectional view of the modified multi-well plate of the present invention.  
         [0016]      FIG. 5  is a perspective view of an extraction template.  
         [0017]      FIG. 6  is a bottom view of a block.  
         [0018]      FIG. 7  is an exploded cross-sectional view of a portion of the extraction template of  FIG. 5  and a portion of a multi-well plate.  
         [0019]      FIG. 8  is a side perspective view of the extraction template and the multi-well plate in a clamping device.  
         [0020]      FIG. 9  is a cross-sectional view of a portion of the extraction template  40  mounted to a portion of the multi-well plate  20 .  
         [0021]      FIGS. 10-12  are graphs of optical density for tests using the present invention.  
         [0022]      FIG. 13  is a graph of static contact angle measurements and surface free energy calculations obtained used in the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0023]      FIG. 1  is a perspective view of a commercially available polystyrene multi-well plate  10 . The multi-well plate  10 comprises twenty-four wells  12  arranged in four rows. The wells  12  of the first and second rows were deposited with a coating formulation diluted in MEK. The coating/MEK mixture reacted with the wells  12  of the plate  10  upon curing at room temperature. Due to this reaction, the wells  12  of the first and second rows have a cloudy, discolored appearance, while the wells  12  in the third and fourth rows remain clear.  
         [0024]     The multi-well plate  10  is commonly used in performing testing or screenings of a wide variety of materials. Specifically, when performing tests on or screenings of various coatings, the multi-well plates may be exposed to a variety of solvents, such as organic solvents, or coatings that contain solvents. The solvent may react with the plate  10  in such a way that adversely affects the use of the plate  10  in the coating screening or test. For instance, the solvent applied to or present in the coating may react with the wells  12  of the plate  10 . Such a reaction adversely affects the ability to obtain a uniform coating on the bottom of the wells  12 , as is desired during high throughput screening of multiple variations of coatings. Such a reaction also contaminates the samples held in the wells  12 , and may otherwise adversely affect the samples or tests performed on the samples.  
         [0025]     The present invention addresses these concerns by modifying the multi-well plate by adding a non-reactive liner to each well  12 . Adding a non-reactive liner to the bottom of each well  12  limits the reaction between the coating in the well  12  and well  12 . As a result, a better, more uniform coating is achieved in the wells  12 .  
         [0026]     The method of forming the modified multi-well plate is illustrated in  FIGS. 2-4A .  FIG. 2  is a perspective view of a multi-well plate  20  having twenty-four wells  22  suitable for use with the present invention. To form the modified multi-well plate of the present invention, an amount of adhesive  24  is applied to the bottom of each well  22 .  
         [0027]     The adhesive  24  may comprise any suitable material, such as glue, epoxy, vacuum grease or the like, capable of holding a liner in the well. Further, the adhesive  24  is preferably chosen to be compatible with the coating or other material to be held in the wells  22 . The adhesive  24  may likewise be chosen so that it is compatible with any tests performed using the multi-well plate  20 .  
         [0028]     For instance, if optical tests will be used in connection with the plate  20 , the adhesive  24  chosen may have the desired optical qualities, such as low auto-fluorescence at various wavelengths of light. In other situations, it maybe desirable to have an optically transparent adhesive layer  24 .  
         [0029]     The adhesive  24  maybe a low-viscosity adhesive suitable for application using a pipette. More preferably, the adhesive  24  is a low viscosity adhesive suitable for application using multiple pipetting performed by a robot to allow for mass production of the plates  20 . The adhesive  24  may have a long pot life, so as not to cure before being covered with a liner. A pot life of 30 minutes or longer is preferred. In addition, thermal curing below 100° C. is preferred.  
         [0030]     One suitable type of adhesive is a silicone two-part coating that is capable of curing within 15 minutes. The silicone based adhesive maybe diluted with a solvent to obtain the desired viscosity. It is desired that the adhesive  24  be viscous enough to be easily spread when a liner is applied, so that the adhesive covers about the entire bottom surface of the wells  22 .  
         [0031]      FIG. 3  is a top view of a liner  30  suitable for use with the present invention. As shown in the example in  FIG. 3 , the liner  30  is circular with a diameter of about 15 mm. The liner  30  maybe formed of any suitable material that will exhibit the desired properties when the multi-well plate is put to use. For instance, suitable materials for the liner  30  may include glass, aluminum, titanium, stainless steel, PVC, polycarbonate, polyetherimide, polyetheretherketone (PEEK), polyimide, polytetraluoroethylene (PTFE), polyethylene, polypropylene, polyurethane, acetate, polyester, nylon, or other materials. If it is desired that the liner  30  be non-reactive with certain solvents or coatings containing solvents, the liner  30  maybe formed of glass. Glass liners  30  are also desirable in many applications because they form a flat surface, desirable for applications of coatings. When formed of glass, suitable sources for the liner  30  are commercially available cover slips for use with microscope analysis.  
         [0032]     The liners  30  can be formed of materials selected based upon the desired application. The material used for the liner  30  can influence biological performance in testing applications. The liners  30  can be punched out of a larger sheet into a desired size and shape.  
         [0033]      FIG. 4A  is a perspective view of a modified multi-well plate  20  in which liners  30  have been applied to the adhesive  24  at the bottom of each well  22 . Once the liners  30  are inserted, the adhesive  24  holds the liners  30  in place, such as by adhering, bonding, or otherwise attaching the liners  30  to the bottom of the wells  22 .  
         [0034]      FIG. 4B  is a side cross-sectional view of the multi-well plate  20  illustrating the present invention. Shown in  FIG. 4B  is a portion of the multi-well plate  20  and two wells  22 . Each well comprises a liner  30  and layer of adhesive  24 . The layer of adhesive  24  is on the bottom surface of the well  22 , and holds the liner  30  in the bottom of the well  22 .  
         [0035]     It will be recognized that multi-well plate  20  can be lined with liners  30  of different materials. For instance, some of the liners  30  can be glass and others formed of aluminum. Plates  20  lined with several types of liners  30  may be useful for biocompatibility studies.  
         [0036]     The liners  30  are preferably sized to ensure a tight fit in the wells  22 . Ensuring the liners  30  fit snugly into the wells  22  helps prevent coatings or solvents that are later applied to the wells  22  from seeping under the liner  30  and adversely reacting with the adhesive  24  used to hold the liner  30  in the well  22 . Such a reaction may lead to contamination of the coating or other material applied to the well  22 .  
         [0037]     The intent of the liner  30  is to minimize the contact with any material other than the liner  30 . However, some reaction between the coating material and the sides of the wells  22  may occur, and may even be preferable in some instances. For instance, the reaction between the coating and the sides of the wells  22  may serve to anchor the coating in the well  22 , so that the coating does not delaminate during subsequent testing. At the same time, the reaction between the coating and the well is limited by the liner  30 , so that the coating samples are less contaminated, and a better, more uniform and flat surface coating is achieved.  
         [0038]     The amount of adhesive  24  applied to the bottom of the wells  22  will vary based on the desired strength of attachment between the liner  30  and the plate  20 . The amount and viscosity of the adhesive is preferably such that when the liner  30  is added, the adhesive  24  easily flows over about the entire bottom surface of the well  22 . If the amount of adhesive  24  is too little, or the adhesive  24  is not of the correct viscosity, the adhesive  24  will not cover the majority of the surface of the liner  30 . In such instances, a coating or solvent applied to the well  22  may seep past the liner, and adversely interact with the adhesive  24 , leading to contamination or other undesirable affects on the coating.  
         [0039]     At the same time, the amount of adhesive  24  applied to the bottom of the wells  22  must not be so great that the adhesive  24  oozes out around the liner  30  when the liner is inserted. It has been found that about 25 micro liters is a suitable amount of adhesive.  
         [0040]     The method of making the inventive multi-well plates comprises the following steps. Each well of a commercially available multi well plate, typically fabricated from non-glass material, has an appropriate amount of adhesive deposited on the bottom. The type of adhesive chosen depends on the desired properties of the finished multi-well plate. The amount of adhesive is an amount effective to adhere the desired liner to the bottom of each well.  
         [0041]     The selected liner may be any suitable material, is preferably the same dimensions of each well, and is placed onto the adhesive drop. Pressure is applied to the liner to spread adhesive over the well bottom between the liner and the well bottom. The adhesive is then allowed to cure for an appropriate period of time. Upon curing, the liner is held in the bottom of the well.  
         [0042]     Yet another method of liner attachment would be to soften the multi-well plate during manufacture, or otherwise cause the wells to expand slightly. Once the multi-well plate is softened, the liner is inserted and the multi-well plate is allowed to contract, shrinking the plate slightly around the liner inserts. This would provide an adhesive free mechanical attachment of the liner to the multi-well plate. If glass slides were installed in this fashion, the resulting plate would have optically transparent wells. Similarly, the inserts could also be inserted as part of the multi-well plate molding process to achieve an adhesive free mechanical bond.  
         [0043]     The following advantages are provided via utilization of this modified format: First, the minimal interaction of coating material with base plate material facilitates a flat and smooth film surface on the anchored liner  30 . Achieving a smooth, flat surface is imperative for accurate testing and screening of the coatings. For instance, in specific applications relating to antifouling and foul-release materials, a smooth flat surface is imperative for accurate analysis via optical imaging techniques.  
         [0044]     Second, a minimal amount of coating-plate interaction may still take place around the perimeter of the well. This small amount of coating-plate interaction serves to “anchor” each coating securely to the bottom of the well. This has been demonstrated to inhibit the delamination of cured coating materials upon immersion in an aqueous environment such as salt water.  
         [0045]     Third, the modified multi-well plates of the present invention are disposable, thereby eliminating the time intensive cleaning required for non-disposable formats. Fourth, the modified multiwell plate format is relatively low in cost. The modified multi-well plates maybe produced for less than about $5 per plate when mass produced. Such a low cost alternative is much more appropriate for high-throughput screening protocols that demand the utilization of numerous plates at one time.  
         [0046]     The modified format could potentially handle a broad range of temperatures. In particular, the modified multi-well plate  20  is an improvement over other types of plates having a glass bottom affixed to polystyrene wells, such as the SensoPlate™. Specifically, the SenoPlates™ may suffer due to different thermal expansion coefficients between the glass bottom and polystyrene top. Because the glass is not continuous in the modified multi-well plastic, the liner  30  and plate  20  can adjust or expand as needed depending on the temperature at which the plastic is utilized. In contrast, the continuous “sheet” of glass bonded to the polystyrene top in the SensoPlate™ design may not be able to adjust or expand appropriately, thereby compromising the integrity of the plate.  
         [0047]     Lastly, the modified multi-well plates are more durable than plates formed entirely or partially of glass. This increased durability allows for use of the modified multi-well plates in a variety of applications. For instance, the multi-well plates can be sent out in kit form, for off-site material deposition, and then returned to the lab for analysis.  
         [0048]     Though disclosed as a twenty-four multi-well plate, the invention is not so limited, and may be useful for multi-well plates having fewer or greater wells. Similarly, though discussed in terms of using a polystyrene multi-well plate, the invention is not so limited. Other multi-well plates may benefit from the modification proposed in this invention. Further, though shown as a flat circular shape, the liner is not so limited. Other shapes of liners maybe more appropriate for various applications, for instance the liner may take the shape of a cup, and extend up the sides of the wells a small distance, or may take the shape of a cylinder, protecting the sides of the wells, but leaving the bottom unlined.  
         [0049]     Applications of the modified multiwell plates described above could have potential and beneficial applications in the following areas, for example: analysis of antifouling materials; culturing of cell lines (i.e., Hepatocyte adhesion); screening of materials for use in coatings of artificial implants (i.e., HPA adhesion); any applications where the interaction of a chemical or biological solution, with a coating or polymeric sample is studied; etc.  
         [0050]     An assay may generally be conducted as follows. Typically, coatings or other materials to be tested are first placed on liners  30  in wells  22  of the multi-well plate  20 . Agents, biofilms or other materials can be added to the wells  22  in order to conduct an assay. At a desired point during an assay, materials can be extracted from the wells  22 . However, biofilms or other materials may become attached and retained to the sides of wells  22  rather than only to the liners  30 . In order to measure only materials on the liners  30 , an apparatus and technique for extracting materials exclusively from the liners  30  can be used. More particularly, an extraction template according to the present invention can be used to withdraw materials substantially exclusively from the liners  30 .  
         [0051]      FIG. 5  is a perspective view of an extraction template  40 , which includes a block  42  and one or more septa  44 , positioned relative a multi-well pate  20  having wells  22 . The septa  44  are generally formed of a chemically inert or resistant material, and have an opening  45   a  for a pipette tip and a skirt portion  45   b.    
         [0052]      FIG. 6  is a bottom view of the block  42 . The block  42  is generally formed to match the dimensions and configuration of a multi-well plate  20  with which it will be used. The block includes one or more holes  46 , which are generally configured to correspond to the size, shape and configuration of the wells  22  of the multi-well plate  20 . In one embodiment, the block  42  is 127 mm by 86 mm by 6.4 mm, the holes  46  are 13.4 mm in diameter, and the holes are spaced 19.4 mm from centers. The block  42  can be aluminum, or any other suitable material. The holes  46  can be machined in the block  42 .  
         [0053]      FIG. 7  is an exploded cross-sectional view of a portion of the extraction template  40  and a portion of a multi-well plate  20 . The extraction template  40  includes septa  44  secured within the holes  46  of the block  42 . An access tube or wedge clamp  48  is positioned within the opening  45  of the septa  44 , for securing the septa  44  within the holes  46  by a press-fit. As shown in  FIG. 7 , a coating material  50  under analysis is positioned on the liner  30  of the multi-well plate  20 . A biofilm  52 , such as a crystal violet stained biofilm, is disposed on top of the coating material  50 . An extraction solution  54 , such as an acetic extraction solution, is located in the well  22  on top of the biofilm  52 . Typically, the coating material  50  and the biofilm  52  have been previously prepared in the multi-well plate  20 , and the extraction template  40  is then used to remove at the biofilm  52  exclusively from a surface of the coating material  50 .  
         [0054]     In order to mount the extraction template  40 , the extraction template  40  is immersed in deionized water briefly and then tapped on a paper towel to remove any remaining water drops before being applied to the multi-well plate  20  containing the biofilm(s)  52 . This step helps to lubricate the septa  44  and facilitate easy application into the wells  22 . The extraction template  40  is positioned such that the septa  44  enter the wells  22  of the multi-well pate  20 .  
         [0055]      FIG. 8  is a side perspective view of the extraction template  40  and the multi-well pate  20  in a clamping device  60 . The clamping device includes a base  62 , one or more clamping levers  64 , and one or more pressure applicators  66 . In the embodiment shown in  FIG. 8 , there are four clamping levers  64  with four pressure applicators  66 , each positioned relative to a corner of the block  42  of the template  40 . Once the extraction template  40  has been applied to the multi-well plate  20 , the plate  20  and template  40  are placed in the clamping device  60  to apply sufficient pressure to the template  40  so as to create a water tight seal at an interface between the coating material  50  and the septa  44 . The pressure applicators  66  apply force in a generally downward direction to the block  42 , which secures the multi-well plate  20  between the template  40  and the base  62  of the clamping device  60 .  
         [0056]      FIG. 9  is a cross-sectional view of a portion of the extraction template  40  mounted to a portion of the multi-well plate  20  (the adhesive  24  is not shown in  FIG. 9 ). In this configuration, the skirt  45   b  of the septa  44  masks or covers the side of the well  22  while leaving the majority of the well  22  bottom exposed for extraction of the biofilm  52  retained on the surface of the coating  50 . The actual area of each coating  50  exposed for analysis, when the extraction template  40  is in place, is less than without the template (e.g., approximately 1.227 cm 2 , as compared to 1.766 cm 2 ). As a result, both the uncoated side wall of the well  22  and the outer periphery of the coating  50  (that may have been contaminated with the polystyrene) are excluded from the analysis. The water tight seal between the template  40  and the multi-well plate  20  prevents the the extraction solution  54  from leaking underneath the septa skirt  45   b  and eluting the crystal violet retained within the biofilm  52  on the side of the well  22  during the extraction procedure.  
         [0057]     Due to the drying and staining procedures, bacterial films remain fixed to the sides of the well  22  during application of the extraction template  40  and can be visualized against the white background of each septa  44 . The extraction solution  54 , for example, 500 μL of 33% glacial acetic acid, is then added through the septa opening  45   a  and allowed to sit for about 10 minutes with occasional shaking to extract the crystal violet from the surface of the coating material  50 . 150 μL aliquots of the eluate are then transferred to clean plates, (e.g., 96-well microtiter plates) for absorbance measurements at 600 nm with a multi-well plate reader. The extraction template  40  can be cleaned via immersion in methanol for 5 minutes to remove any residual crystal violet adsorbed onto septa  44 .  
       EXAMPLES  
       [0058]     The following examples demonstrate possible use of the modified multi-well plates according to the present invention. Modified multi-well plates were utilized to assess the initial settlement/biofilm formation obtained on 4 different types of external reference coatings routinely utilized as controls for assessing antifouling/foul-release properties. Three silicone based resins (Dow Corning 3140, GE RTV-11 and GE T2-silastic) and an acrylate (Paraloid B-44S 40%, PMM) were deposited into a 24-well, glass coverslip/epoxy anchored modified polystyrene plate. The resins were allowed to cure for &gt;=24 hours at room temperature and were subsequently pre-leached in deionized water for &gt;=24 hours to remove any residual curing agent or solvent prior to analysis.  
         [0059]     Three different marine bacteria were utilized to evaluate the initial settlement/biofilm formation on each coating type ( Halomonas marina,Pseudoalteromonas atlantica, Vibrio anguillarum ). Coatings were challenged with each bacterium individually for about 18 hours at 28° C. Methodologies adapted from the current literature were employed to carry out the quantification of biofilm obtained. See S. Stepanovic, D. Vukovic, I. Dakic, B. Savic, M. Svabic-Vlahovic. 2000. “A modified microtiter-plate test for quantification of staphylococcal biofilm formation”. J.  OF  M ICROBIOL.  M ETHODS.  40:175-179; D. Djordjevic, M. Wiedmann, and L. A. McLandsborough. 2002. “Microtiter Plate Assay for Assessment of  Listeria monocytogenes  Biofilm Formation”. A PPLIED AND  E NVIRON.  M ICROBIOL.  68(6):2950-2958. Briefly, planktonic and loosely adherent bacteria were removed from each well containing one of the external reference coatings by rinsing twice (2×) with 1.0 mL nanopure water. The remaining, adherent biofilm was immediately stained with 0.5 mL of 1% weight by volume (w/v) crystal violet solution for about 15 minutes. Excess stain was removed by rinsing three times (3×) with 1.0 mL of nanopure water. Plates were then inverted and firmly tapped several times against a paper towel to ensure that all remaining, non-bound stain was removed from each well. Plates were then allowed to dry at room temperature for about 1 hour or until visibly dry. 0.5 mL of a 33% by volume (v/v) glacial acetic acid/nanopure water solution was then added to each well for about 10 minutes (with gentle shaking) to elute the bound stain. 0.15 mL of the crystal violet/acetic acid solution was then transferred to a 96-well plate and measured for optical density (OD 600 ) with a standard multiwell plate reader.  
         [0060]     The cationic dye crystal violet (cv) is a standard biomass indicator wherein the OD 600  measurement is directly proportional to the biomass obtained on the surface of each coating. Therefore, a comparison of the OD 600  readings obtained for each coating type is utilized to evaluate their ability to inhibit settlement and initial biofilm growth. This information enables one to successfully identify superior performing candidates that warrant further testing and characterization.  FIGS. 10, 11  and  12  are graphs showing that the results from each of the bacteria utilized are similar. This was anticipated from investigating the current literature as the marine bacteria utilized have a tendency to settle on more hydrophobic or lower surface energy surfaces. See L. K. Ista, V. H. Perez-Luna, and G. P. Lopez. 1999. “Surface-Grafted, 15 Environmentally Sensitive Polymers for Biofilm Release”. A PPLIED AND  E NVIRON.  M ICROBIOL.  65(4):1603-1609. As shown in the graph of  FIG. 13 , static contact angle measurements (series  1 ) and surface free energy (series  2 ) calculations with deionized water as the contact solvent were made for each of the four coating types.  
         [0061]     Thus, the foregoing examples demonstrate how high-throughput testing and screening can be accomplished utilizing the modified multi-well plates of the present invention. More particularly, the foregoing examples demonstrate how biofilms can be used to test coating samples disposed on liners of multi-well plates according to the present invention.  
         [0062]     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes maybe made in form and detail without departing from the spirit and scope of the invention.