without more information it is difficult to make a suggestion but:
We use normally PBS/5%NCS for blocking and it always works (except in
some cases when the antigen is a carbohydrate). Maybe your blocking
solution is not the problem, but there are some other cross-reactivities
in the test system. Another guess would be to try another elisa-plate
> I am doing an Elisa. I get my first protein to bing to the tray then i block then i add my second protein. However i cannot get the blocking step to work. Ive used BSA, skim milk, tryptone peptone, egg yolk, various cell lysates. Has anyone got an good blocking agents thats relatively cheap and available?