Simplified Indirect Complement-Fixation Test Applied to Newcastle Disease Immune Avian Serum

Immunological Reactions in Viral Diseases

“…These obser· vations led to the technique of the "indirect" complement-fixation test (187) which, first applied to S. puUorum of turkeys (188), was extended by Wolfe et at. (189) to Newcastle disease of chickens. The latter authors, who simplified the tech nique of the test, found very good correlation between specific antibodies measured by means of the indirect complement-fixation test and the hemag glutination-inhibition test.…”

The Demonstration of Substances in Human Sera Which Inhibit Complement Fixation in Antigen-Antibody Systems of Lymphogranuloma Venereum, Psittacosis, Mumps, Q Fever, and Lymphocytic Choriomeningitis

“…Such inhibitory activity generally is thought to be due to the presence in the sera of specific antibodies which, although they are not capable of forming complement-fixing complexes with the antigen, nevertheless combine specifically with the antigen and bind it so that it no longer is available for combination with complementfixing antibodies in a second immune serum. On the assumption that the inhibitory substances actually represent a type of antibody, so-called "indirect" complement fixation or complement fixation inhibition tests have been devised to titrate the inhibitory activity of immune sera of the species which do not produce complementfixing antibodies (Rice, 1948a;Rice 1948b;Wolf et al, 1949; Downie and MacDonald, 1950;Karrer et al, 1950b;Rice, 1951). This test has had its greatest application in the detection of ornithosis in certain avian species such as chickens, ducks, turkeys, and geese, which do not produce complement-fixing antibodies in response to infection with the disease agent.…”