Application of pepsin-digested horse antibodies for quantitative immunoelectrophoresis

The majority of the precipitating antibodies in hyperimmune horse serum belong to the beta globulins, as demonstrated by reversed immunoelectrophoresis. As these antibodies migrate in agarose gel during electrophoresis in conventional pH = 8.6-8.9 buffers, horse antiserum cannot be used satisfactorily for quantitative immunoelectrophoresis. On pepsin digestion of horse antiserum F(ab)' 2 fragments are generated which migrate with the gamma globulins. This cleaved product works well in quantitative immunoelectrophoretic techniques.