System for pH-neutral stable electrophoresis gel

1. A method for performing discontinuous gel electrophoresis, comprising:

a) selecting a discontinuous electrophoresis system from a pair of discontinuous electrophoresis systems, wherein the electrophoresis system is selected based on a molecular weight of a protein and the separation characteristics of the electrophoresis system, wherein each electrophoresis system of the pair of electrophoresis systems separates proteins of different molecular weights, and wherein the pair of electrophoresis systems comprises:

i) an electrophoresis separating gel comprising acrylamide and a gel buffer having a pH between 6 and 8, wherein the gel buffer comprises a primary organic amine or a substituted amine with a pK a near neutrality; and

ii) two separate running buffers each comprising a different zwitterionic compound, and

b) performing electrophoresis to resolve the protein in a sample using the selected electrophoresis system.

2. The method of claim 1 , wherein the running buffer in each electrophoresis system further comprises a primary organic amine or a substituted amine.

3. The method of claim 2 , wherein the primary organic amine or the substituted amine is different for each electrophoresis system of the pair of electrophoresis systems.

4. The method of claim 1 , wherein one of the different zwitterionic compounds is [N-(2-acetamido)]-2-aminoethanesulfonic acid (ACES).

5. The method of claim 1 , wherein one of the different zwitterionic compounds is 24N-morpholino]-2-hydroxypropanesulfonic acid (MOPSO).

6. The method of claim 1 , wherein one of the different zwitterionic compounds is 3-N-morpholinopropanesulfonic acid (MOPS).

7. The method of claim 1 , wherein one of the different zwitterionic compounds is 2-N-morpholinoethanesulfonic acid (MES).

8. The method of claim 1 , wherein one of the different zwitterionic compounds is piperazine-N,N′-2-ethanesulfonic acid (PIPES).

9. The method of claim 1 , wherein one of the different zwitterionic compounds is N-Tris-(hydroxymethyl)-2-ethanesulfonic acid (TES).

10. The method of claim 1 , wherein one of the different zwitterionic compounds is N,N-bis-(hydroxyethyl)-2-aminoethanesulfonic acid (BES).

11. The method of claim 1 , wherein one of the different zwitterionic compounds is N-2-hydroxyethyl-piperazine-N-2-ethanesulfonic acid (HEPES).

12. The method of claim 1 , wherein one of the different zwitterionic compounds is 3-(N-Tris-(hydroxymethyl) methylamino)-2-hydroxypropanesulfonic acid (TAPSO).

13. The method of claim 1 , wherein the two different zwitterionic compounds are 3-N-morpholinopropanesulfonic acid (MOPS) and 2-N-morpholinoethanesulfonic acid (MES).

14. The method of claim 1 , wherein the buffer gel electrophoresis system further comprises a reducing agent that is negatively charged at a neutral pH.

15. The method of claim 1 , wherein the electrophoresis separating gel is polymerized using 5% crosslinker.

16. The method of claim 1 , further comprising casting the electrophoresis separating gel with a gel buffer having a pH of between 6 and 8, prior to performing electrophoresis.

17. The method of claim 16 , wherein the electrophoresis separating gel is cast with a gel buffer having a pH of between 6.5 and 7.5.

18. The method of claim 16 , wherein the electrophoresis is performed at least 1 year after the gel has been cast.

19. The method of claim 16 , wherein the electrophoresis is performed between 2 months and 1 year after the gel has been cast.

20. The method of claim 16 , wherein the electrophoresis is performed 1 year after the gel has been cast.

21. The method of claim 16 , wherein the electrophoresis separating gel is cast in a disposable cassette.

22. The method of claim 21 , further comprising after the casting, and before the electrophoresis, storing the gel in a sealed package.

23. The method of claim 16 , wherein the electrophoresis separating gel is cast by an outside vendor.

24. The method of claim 1 , wherein the electrophoresis is carried out in an electrophoresis separating gel comprising between 3 and 25 (wt/vol)% acrylamide.

25. The method of claim 1 , wherein the electrophoresis is carried out in an electrophoresis separating gel comprising between 8 and 20 (wt/vol)% acrylamide and sodium dodecyl sulfate (SDS).

26. The method of claim 1 , wherein the pair of electrophoresis systems resolves proteins between 2 kDa and 200 kDa.

27. A pair of discontinuous electrophoresis systems comprising:

i) an electrophoresis separating gel comprising acrylamide and a gel buffer having a pH between 6 and 8, wherein the gel buffer comprises a primary organic amine or a substituted amine with a pKa in the range of 6 to 8; and

ii) two separate running buffers each comprising a different zwitterionic compound.

28. The pair of electrophoresis systems of claim 27 , wherein the running buffer in each electrophoresis system further comprises a primary organic amine or a substituted amine.

29. The pair of electrophoresis systems of claim 27 , wherein the primary organic amine or the substituted amine is different for each electrophoresis system of the pair of electrophoresis systems.

30. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is [N-(2-acetamido)]-2-aminoethanesulfonic acid (ACES).

31. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is 2-[N-morpholino]-2-hydroxypropanesulfonic acid (MOPSO).

32. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is 3-N-morpholinopropanesulfonic acid (MOPS).

33. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is 2-N-morpholinoethanesulfonic acid (MES).

34. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is piperazine-N,N′-2-ethanesulfonic acid (PIPES).

35. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is N-Tris-(hydroxymethyl)-2-ethanesulfonic acid (TES).

36. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is N,N-bis-(hydroxyethyl)-2-aminoethanesulfonic acid (BES).

37. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is N-2-hydroxyethyl-piperazine-N-2-ethanesulfonic acid (HEPES).

38. The pair of electrophoresis systems of claim 27 , wherein one of the different zwitterionic compounds is 3-(N-Tris-(hydroxymethyl) methylamino)-2-hydroxypropanesulfonic acid (TAPSO).

39. The pair of electrophoresis systems of claim 27 , wherein the two different zwitterionic compounds are 3-N-morpholinopropanesulfonic acid (MOPS) and 2-N-morpholinoethanesulfonic acid (MES).

40. The pair of electrophoresis systems of claim 27 , wherein the buffer gel electrophoresis system further comprises a reducing agent that is negatively charged at a neutral pH.

41. The pair of electrophoresis systems of claim 27 , wherein the electrophoresis separating gel has 5% by weight crosslinker.

42. The pair of electrophoresis systems of claim 41 , wherein the electrophoresis separating gel has a gel buffer having a pH of between 6.5 and 7.5.

43. The pair of electrophoresis systems of claim 41 , wherein the electrophoresis separating gel is at least 1 year old.

44. The pair of electrophoresis systems of claim 41 , wherein the electrophoresis separating gel is between 2 months and 1 year old.

45. The pair of electrophoresis systems of claim 41 , wherein the electrophoresis separating gel is 1 year old.

46. The pair of electrophoresis systems of claim 41 , wherein the electrophoresis separating gel is in a disposable cassette.

47. The pair of electrophoresis systems of claim 46 , wherein the disposable cassette is in a sealed package.

48. The pair of electrophoresis systems of claim 27 , wherein the electrophoresis separating gel comprises between 3 and 25 (wt/vol)% acrylamide.

49. The pair of electrophoresis systems of claim 27 , wherein the electrophoresis separating gel comprises between 8 and 20 (wt/vol)% acrylamide and sodium dodecyl sulfate (SDS).