antiserum

The antiserum used for the precipitin reaction was obtained by treating a rabbit with human blood serum.

The Libby Photronreflectometer was used to measure the turbidities developed by the interaction of antigen and antiserum.

In every series of tests the amount of antiserum was held constant and the amount of antigen was varied.

More than two series, however, resulted in little or no improvement of the reactivity of the antiserum.