BSA purity for Western Blot? - What BSA to use? (Aug/11/2005 )

Can somebody recommend a purity of BSA to use for antibody incubation that does not yeild background noise in Western Blots. Right now I am using 96% pure Fraction V from sigma and I am beginning to suspect it might be causing background. Can anybody recommend something that they use and where they buy it?

Thanks

I'm pretty sure I'm using a similar grade purity BSA from Sigma, and I'm having no background problems. Are you making up your BSA buffers fresh each time, storing them in the fridge, making a stock or what?

Plus, each antibody is different - I've got some antibodies that perform brilliantly with nonfat milk as a blocking agent but lousy with BSA, and vice versa - so probably I would try messing about with different blocks and/or wash steps before deciding that the antibody itself gives high background.

How bad is the background - like messy, or totally can't-see-anything?