Modified micromethod for detection of human Fc receptor-like material.

Soluble FcR-like material can be demonstrated in the culture supernatants of activated lymphocytes. We modified as assay for its detection which was based upon inhibition of complement dependent hemolysis, an unreliable phenomenon in our hands. The micromethod presented was developed using the culture supernatants of FcR producing and FcR non-producing lymphoblastoid cell lines. Suppression of hemolysis was consistently observed providing the assay was performed below 22 degrees C. It is suggested that the classical pathway of complement activation is inhibited by this material but not the alternative pathway. By this method FcR material can be detected in small cultures where cells are limited in number.