The Fluorescent Antibody Technique Applied to Titration and Identification of Antigens in Solutions or Antisera. ∗

Summary

Cellulose acetate discs or agar are useful supporting media for titration or identification of antigen or antibody. The cellulose acetate fluorescent spot (CAFS) method is simple to perform and read and requires only a few lambda of antiserum or antigen; the fluorescent impregnated agar (FIA) method is essentially the same as the fluorescent antibody technique applied to tissue. In the titration of ABSA, AHGG and AHS both fluorescent methods were more sensitive than the ring precipitin test, when the indirect staining was used. In addition the methods permitted selection of proper fixatives for a given antigen and determination of the proper concentration of labelled antisera for demonstration of tissue antigen.