Detection of protein contaminants in biological preparations by discontinuous counterimmunoelectrophoresis.

Acidic proteins (serum albumin through beta(2) globulin) can be rapidly detected by the discontinuous counterimmunoelectrophoresis method in which the protein under test is allowed to react electrophoretically with specific antiserum. In the test, acidic proteins move towards the anode and cross over antibodies moving towards the cathode. The method is several thousand times more sensitive than the Lowry test, for it can detect picogram amounts of protein. With this method, foreign proteins (chicken allantoic fluids or bovine serum) were detected in virus vaccines manufactured for human use and in commercial "monospecific" immunological reagents.