An Agglutinating Factor in Insect Hemolymph1

Abstract

In testing the hemolymph of the large milkweed bug, Oncopeltus fasciatus (Dallas), for nonprecipitating antibodies to rabbit serum, the method of Boyden (1951) was employed. This method involves coating human erythrocytes with tannic acid and antigen before exposure to the immune serum. If antibody is present in the serum it will cause a visible clumping of the erythrocytes.