AFFINITY MEMBRANE IDENTIFICATION OF IMMUNOGLOBULIN SUBCLASS IN HYBRIDOMA SCREENING

Monoclonal hybridomas secrete immunoglobulins with a single antigen sp ecificity and distinct class/subclass structure. Hybridoma management has commonly incorporated tests of antigen specificity into early scre ening procedures, but has not typically utilized assays of immunoglobu lin structure. In this article, we describe a technique of class/subcl ass typing using polyvinylidene difluoride affinity membranes and a co lorigenic enzymatic amplification system. The typing of monoclonal ant ibody structure was sufficiently sensitive to permit its routine use w ithin several weeks of hybridoma fusion. The information obtained from early and routine class/subclass determinations included a semiquanti tative assessment of monoclonal antibody concentration. In addition, t he detection of a single immunoglobulin class/subclass in a microtiter well supernatant supported the possibility that the colony was monoty pic. The application of class/subclass typing and Poisson statistics t o hybridoma fusions provided a numerical estimate of the probability o f colony monotypia.