The use of two-dimensional immunoelectrophoresis for the characterization of antigens of BCG substrains.

The usefulness of the method of two-dimensional immunoelectrophoresis (2D-IEP) in comparative studies and characterization of the antigenic spectra of various BCG substrains have been estimated. The BCG substrains used were: substrain BCG-Rio de Janeiro, substrain BCG-Poland, form-rough (R) and substrain BCG-Poland, form-smooth (S). The 2D-IEP technique was found to give characteristic immunoelectrophoretic patterns of antigenic composition of the different BCG substrains. The number of precipitin peaks was usually over 20, that is more than detected by conventional immunoprecipitation techniques such as immunodiffusion and immunoelectrophoresis in agar gel (ID, IE).