Contaminating Antibodies May Produce Unexpected Reactions in Counter-Current Immunoelectrophoresis

Abstract

ABSTRACT: The possibility of contaminating antibodies in an antiserum causing reactions in countercurrent immunoelectrophoresis at low antigen concentrations, though not at higher concentrations, was raised, and also argued against, in a recent, widely-publicized legal case.

This study has demonstrated that, in this technique, precipitin bands can be produced in tests involving low concentrations of antibodies only where there are also low concentrations of antigen, not where there are higher concentrations of antigen. These results indicate that, under appropriate circumstances, in counter-current Immunoelectrophoresis, a low concentration of contaminating antibodies in an antiserum could produce a precipitin band with a low concentration of an unsuspected antigen. This possibility points up the necessity of establishing the identities of the reacting antigens and antibodies in such tests, using a different procedure, such as the double radial immunodiffusion (Ouchterlony) technique. It is suggested that the value of counter-current immunoelectrophoresis in forensic testing should be given consideration.