Some sites on sections can non-specifically bind primary antibodies and lead to false-positive results. The blocking serum is normally from the same species with the secondary antibody. Antibodies in the serum can bind the sites that cross-react with primary antibodies. Alternatively FBS (fetal bovine serum), BSA (bovine serum albumin) or goat serum can be used, but from the different species as the primary antibodies.
Generally, the blocking process is 10-30 min, at room temperature, to prevent an over-blocking.
|To avoid non-specific binding of antibodies|