Duplicate plating of immune cell products: analysis of globulin class secretion by single cells

Antibodies secreted by individual immune cells were collected focally in very thin "original" and "imprint" layers of agar containing the target antigen, sheep erythrocytes. Identical treatment of both layers led to mirror image patterns of hemolytic plaques. Development of one layer for immunoglobulin M hemolysins and the other for immunoglobulin G hemolysins produced unrelated plaque patterns indicating that few, if any, cells simultaneously release substantial amounts of both gammaM and gammaG antibodies.