Assay devices for combinatorial libraries

1. An apparatus suitable for conducting an assay for a combinatorial library, wherein the apparatus comprises:

a block;

a plurality of wells disposed on a top surface of the block, wherein said plurality comprises at least 10,000 wells within the block, each well in said plurality comprising:

a cylindrical opening defined by a side wall, the side wall having circular cross sections at any position along the side wall, the cylindrical opening penetrating partly into the block;

a floor, wherein said floor comprises a hydrophilic target capturing element adherent thereto and impeding movement of a target when added to said well, the hydrophilic target capturing element comprising a film; and

a hydrophilic coating on the side wall; and

a hydrophobic layer disposed on the top surface of the block and between each well, the hydrophobic layer configured to restrict spill-over of an aqueous solution between wells,

wherein minimum distances from edges of each of the wells to edges of the respective one or more nearest neighboring wells in said plurality of wells are from about 10 microns (μm) to about 50 μm, and

wherein each of the wells has a well diameter from about 30 μm to about 250 μm and a well depth from about 30 μm to about 400 μm.

2. The apparatus according to claim 1 , wherein a density of the wells is from at least 10 wells per mm 2 to about 400 wells per mm 2 .

3. The apparatus according to claim 2 , wherein a density of the wells is from about 40 wells per mm 2 to about 150 wells per mm 2 .

4. The apparatus according to claim 1 , wherein the minimum distances from the edges of each of the wells to edges of the respective one or more nearest neighboring wells are from about 10 μm to about 30 μm.

5. The apparatus according to claim 1 ,

wherein the target capturing element is configured to capture a mammalian cell maintained in an aqueous growth medium for the mammalian cell,

wherein the aqueous growth medium is configured to maintain the viability of the mammalian cell in solution, and

wherein the aqueous growth medium is maintained in at least one of the at least 10,000 wells.

6. The apparatus according to claim 5 , wherein the target capturing element comprises poly-D-lysine.

7. The apparatus according to claim 4 , wherein the distance along the top surface from the nearest edge of the first well to the nearest edge of the second well is from about 15 μm to about 25 μm.

8. The apparatus of claim 1 , wherein the wells comprise at least about 100,000 wells.

9. The apparatus of claim 1 , wherein the hydrophobic layer comprises a biologically compatible, hydrophobic material selected from polyethylene, polypropylene, block copolymers of ethylene and propylene, polytetrafluoroethylene, (trichloro)octadecyltsilane (OTS), amorphous fluoropolymers, and polydimethylsiloxane (PDMS).