The addition of antigen to the buffer over the ascending and descending limbs of a free boundary electrophoresis cell containing antiserum results in an immunologically specific disturbance of the γ-globulin boundary. This technique provides a sensitive method for detecting either antigen or antibody.
The antigens studied have been bovine serum albumin, Pneumococcus polysaccharide (SSSII), Boivin-type antigen from E. coli and bovine serum globulin.
The disturbance may develop in the ascending and/or descending limb depending upon whether the antigen migrates slower, faster, or at the same rate as the antibody component.
The method detects as little as 0.1 µg of antigen/ml in the buffer and as little as 10 µg of precipitating antibody/ml in the serum compartment of the cell.
The E. coli antigen differed from the others in that it induced γ-globulin boundary disturbances when tested against normal sera, providing further evidence for the presence of antibodies against E. coli in normal sera.
The descending β-boundary disturbance frequently observed during routine free-boundary electrophoretic analysis can be eliminated by adding as little as 0.24 mg of albumin/ml to the buffer over the descending limb.
Some nonspecific boundary disturbances which may be encountered when attempting to apply this method to detect antigen and antibody are discussed.
Presented in part to the American Association of Immunologists, April 1954 (1).