I have just been asked a good question. Do we need to do preabsorption/preimmune serum control in Western blot. I usually test my antibodies using a dot blot technique..and include the samples (i.e. protein lysate), a BSA control (negative) and a secondary antibody (positive). Is this then sufficient to say that the antibody is specific based on the correct size band detected in WB?
I would include preimmune serum control (negative isotype control) in my IHC analysis, but is this also necessary for WB?