The conglutination phenomenon: IV. The importance of the choice of complement when examining antisera for the presence of complement-fixing or complement-absorbing antibodies

Abstract

1. Anti-mallein and anti-typhoid sera produced in various animal species, including man, have been examined for complement-absorbing antibodies using the complements of the pig, horse, cat, man, dog, and guinea-pig, which is possible if use is made of the conglutinating complement-absorption test as well as the haemolytic complement-fixation test.2. Complement-fixing antibodies which are not demonstrable when some complements are used may be detected when other complements are used; for example, antibodies to mallein in human antisera were only detected when the sera were tested with horse and cat complements.3. These early results are published at this stage because of the obvious possible application of these methods in laboratory serological diagnosis. Further work is in progress to elucidate the underlying reasons for these observations.4. The implications of the results are discussed from the practical and theoretical aspects.