[Production of antiserum for preparation of FITC-conjugated immunoglobulins intended for poxvirus detection]

The experience of using sheep as donors of hyperimmune smallpox antiserum produced by immunization with vaccinia virus grown in the homologous tissue is described. In the preparatory stage of immunization four intravenous or intramuscular injections of a low dose of the antigen were used. Subsequently, as the need in the serum arose (10--14 days before) the animals were given a "hit" dose of the antigen (20 ml) intravenously. With this immunization schedule it was possible to obtain smallpox antisera containing precipitins (in a titer of 1:32), hemagglutinins (1:1280), and antibody detectable by the indirect immunofluorescence technique (1:2560). Then, from these sera, using two precipitations of the immunoglobulin fraction with ammonium sulfare, antipox FITC-conjugates were prepared which were highly active and specific, and were as good as FITC-conjugates prepared from rabbit hyperimmune sera.