Various procedures were tried for improving the quality of group C arbovirus hemagglutinins derived from suckling-mouse liver. After separation of hemagglutinating (HA) and complement-fixing antigens by centrifugation, liver preparations were still too insensitive for use in hemagglutination-inhibition (HI) tests. Sonication produced marked improvement in HA titer, with no evidence that this was due to splitting of the virus particle; however, HI reactivity was still inadequate. Subsequent adsorption onto calcium phosphate (brushite form) followed by stepwise elution resulted in antigens of high quality.
Modified methods are described for preparation of sucrose-acetone antigens and for acetone extraction of immune mouse ascitic fluids.
Present address: Faculté de Médecine de Paris, Institut de Parasitologie, 15, rue de l'Écolede-Médecine, Paris, VI, France.
The Yale Arbovirus Research Unit is supported in part by The Rockefeller Foundation.