Studies on the optimal immunization schedule of the mouse as an experimental animal. The effect of antigen dose and adjuvant type.

This study was undertaken to establish the optimal immunogen dose for immunization of mice, using a viomycin-protein conjugate as a hapten immunogen. It was found that specific immunoglobulin G (IgG) formation depends on both the dose of antigen and the type of adjuvant: the optimal antigen dose for an immune response is quite different depending on whether the mice are being treated with Freund's complete adjuvant (FCA) or Freund's incomplete adjuvant (FICA). The total IgG amount depends mainly upon the type of adjuvant used. FCA gave the double the level of IgG compared to that obtained with FICA. The antigen dose was found to have little influence on the total production of IgG. Mice given a primary immunization with 10 micrograms of antigen emulsified in FCA and then given a booster with the same amount of antigen emulsified in FICA produced a strikingly high level of specific anti-viomycin antibody of over 2.5 mg/ml of the antiserum. It was also found that decreases in the weight of the mice were related to the kind of adjuvant used as well as to the level of the specific antibody formed.