Measurement of monoclonal antibody concentrations in hybridoma cultures: Comparison of competitive inhibition and antigen capture enzyme immunoassays

Competitive inhibition and antigen capture enzyme immunoassays were compared for the measurement of mouse monoclonal IgG1 antibody produced by a hybridoma culture. Both methods yielded standard curves that were linear over several orders of magnitude, and both were comparable in sensitivity (10 ng/ml). However, the slope of the antigen capture curve was flatter than the slope for competitive inhibition. This difference in slope, coupled with a larger average standard deviation for each point on the standard curve for antigen capture, resulted in a significantly larger range of variability in IgG1 levels. It is concluded that the competitive inhibition enzyme immunoassay method is better suited to the precise quantification of mouse monoclonal antibodies in hybridoma culture supernatants.