Screening assays and methods
Screening assays and methods of performing such assays are provided. In certain examples, the assays and methods may be designed to determine whether or not two or more species can associate with each other. In some examples, the assays and methods may be used to determine if a known antigen binds to an unknown monoclonal antibody.
1. A method of screening a monoclonal antibody comprising:
(a) reversibly sealing a moldable slab to a substrate, said moldable slab comprising an array of microwells, each microwell having a side or diameter of less than 100 microns, wherein microwells of said array contain a single or a few antibody-producing cell(s) that secrete monoclonal antibodies in a volume of 10 nanoliters or less of fluid in said microwells; wherein the substrate's surface facing the microwells is modified such that it acts to retain such secreted monoclonal antibodies on the surface;
(b) allowing said antibody-producing cell(s) to secrete said monoclonal antibodies in said volume such that monoclonal antibody secreted from the antibody-producing cell(s) in said volume is retained by the surface of the substrate sealed to the moldable slab;
(c) removing the substrate from the moldable slab; and
(d) exposing the retained monoclonal antibody to an antigen to test the retained monoclonal antibody for a desired binding specificity.
2. The method of claim 1 wherein each microwell has a diameter of 10 to 100 microns.
3. The method of claim 2 wherein each microwell has a diameter of 50 to 100 microns.
4. The method of claim 1 wherein the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 10 picoliters to 10 nanoliters.
5. The method of claim 1 wherein the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 1 nanoliter or less.
6. The method of claim 1 wherein the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 100 picoliters to 1 nanoliter.
7. The method of claim 1 wherein the antigen is labeled.
8. The method of claim 7 wherein the antigen is fluorescently labeled.
9. The method of claim 1 wherein the substrate is a glass substrate.
10. The method of claim 1 wherein the moldable slab is made of poly(dimethylsiloxane).
11. The method of claim 1 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
12. The method of claim 11 wherein the protein is Protein A.
13. The method of claim 11 wherein the protein is Protein G.
14. The method of claim 11 wherein the protein is a secondary antibody.
15. The method of claim 1 wherein steps (a)-(d) are performed in less than 24 hours.
16. The method of claim 15 wherein steps (a)-(d) are performed in less than about 12 hours.
17. The method of claim 1 wherein the step of reversibly sealing forms a substantially fluid tight seal between the moldable slab and the substrate.
18. The method of claim 1 wherein
each microwell has a diameter of 10 to 100 microns; and
the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 1 nanoliter or less.
19. The method of claim 18 wherein the step of reversibly sealing forms a substantially fluid tight seal between the moldable slab and the substrate.
20. The method of claim 19 wherein the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 100 picoliters to 1 nanoliter.
21. The method of claim 1 wherein
each microwell has a diameter of 10 to 100 microns;
the antibody-producing cell(s) secrete the monoclonal antibodies in a volume of 100 picoliters to 1 nanoliter;
the substrate is a glass substrate;
the moldable slab is made of poly(dimethylsiloxane);
the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure; and
the step of reversibly sealing forms a substantially fluid tight seal between the moldable slab and the substrate.
22. The method of claim 2 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
23. The method of claim 3 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
24. The method of claim 4 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
25. The method of claim 5 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
26. The method of claim 8 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
27. The method of claim 15 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
28. The method of claim 17 wherein the surface of the substrate is coated with a protein that recognizes the constant region of an antibody's structure.
29. The method of claim 1 wherein the substrate comprises a plastic material.
30. The method of claim 19 wherein the surface of the substrate facing said microwells is substantially planar.