Louis R. Sibal

Mammary Tumor Virus Antigen: Sensitive Immunoassay

A rapid, sensitive immuno-assay for mammary tumor virus antigen based on inhibition of passive hemagglutination has been developed. The method permits measurement of this antigen in mouse milk from which the fat has been removed.

Production of Antibodies by Adult Hen Spleen Cells Transferred to Chick Embryos.

Summary Spleen cell suspensions from normal hens inoculated onto CAMs with BSA, or after in vitro contact with BSA, failed to produce demonstrable antibodies. Whole spleen cell and spleen white cell suspensions, taken from previously normal hens 36 to 48 hours after intravenous injection of BSA and inoculated onto CAMs, produced significant amounts of antibody without further contact with antigen 4 to 7 days after transfer. The white cell suspensions produced somewhat more antibody than did the whole spleen suspensions. Whole spleen cell suspensions, taken from hens 48 hours after intravenous reinjection of BSA, produced significant amounts of antibody, without further contact with antigen, 2 to 6 days after transfer to CAMs. Whole spleen cell suspensions, from hens stimulated by BSA injection more than 7 days previously, inoculated onto CAMs with BSA, or after in vitro contact with BSA, failed to produce demonstrable antibodies.

Enhanced Production of Antibody to a Murine Leukemia Virus (Rauscher) in the I lost of Origin

Summary Potent antiserum was prepared against a murine leukemia virus (Rauscher) in BALB/c mice by an immunizing regimen consisting of two inoculations in which the second one is given only after an interval sufficient for the primary response to wane. An interval of 90 days or more following a primary injection of antigen emulsified in Freunds adjuvant was optimal. The early antibody response to Rauscher virus in ET-treated mice is also described. The gamma-M antibodies, which appeared as early as the third day after a single antigenic stimulus, were readily detected by HA tests, but failed to precipitate with virus in immunodiffusion tests.

Hemagglutination studies of the viral antigen in a murine leukemia (Rauscher).

Summary The tanned cell HA and HAI methods were adapted for study of a murine leukemia virus (Rauscher). The tests using antibody prepared in Rhesus monkeys were shown to be sensitive and specific for detection and estimation of virus and of anti-viral antibody. Antisera produced in 14 individual monkeys had titers ranging from 1:20 to 1:5,120 with a geometric mean of 1:320 when tested against JLS-V5 sensitized SRBC. As little as 0.2 μg/ml of viral protein was detected by HAI.