Summary

The solid-phase antibody method using antibody coated polystyrene tubes as described by Catt offers several advantages: an increase in “damage” to labelled hormone decreases the sensitivity, but not the precision of the assay. Incubation damage can be avoided by two-step incubation. The quality of an antiserum required for use in the solid-phase antibody technique has been found to rely on the concentration of gamma globulins directed specifically against the antigen (hormone): The total gamma globulin fraction of an anti-ACTH antiserum could not be used for coating. The isolated anti-ACTH-gammaglobulins, however, could be coated to polystyrene, which is shown by a consecutive tracer binding of about 40%.