THE USE of FLOW CYTOMETRY FOR the RAPID CHARACTERIZATION of MONOCLONAL ANTIBODY PRODUCTION

Flow cell cytometry is reported here as a rapid fluorescent immunoassay method to characterize monoclonal antibody production in hybridoma cultures. Actinomyces viscosus was the bacterium chosen as a model to illustrate this procedure. Fluorescein isothiocyanate (FITC), coupled to staphylococcal Protein A (PA), was used as the fluorescent marker to detect and quantitate antigen-antibody reactions. Flow cell cytometry was also used with rabbit polyclonal antibodies to A. viscosus coupled with PAFITC for comparison and verification of the two procedures. Over 25,000 individual bacteria could be analyzed in a single cytometer injection within 2 min. the data, presented as histograms and figures, supported the feasibility of this method and also provided an in-depth analysis of the degree of fluorescence, cell size, distribution and light scatter not available with most other immunoassay methods.