It has been found that antigens suitable for routine tests for complement-fixing or precipitating antibodies in the sera of suspected cases of chickenpox or zoster can be readily prepared from tissue cultures of human amnion infected with zostervaricella virus.
Useful antigens were obtained when infected cells were incubated at 36°–38° C. in bovine amniotic fluid diluted with an equal volume of Hanks' solution.
Virus strains gave a good yield of antigen after two or more passages in tissue culture but one strain in its fiftieth passage did not.
Harvested culture fluids require 5- to 20-fold concentration for complement-fixation tests and 100- to 200-fold for precipitation tests; concentration of culture fluids was readily effected by drying from the frozen state after removal of salts by dialysis. Tissue culture antigens gave results by complement-fixation tests which were comparable to those given by a good vesicle fluid.
Some evidence was obtained that the antigens responsible for precipitation were not identical with those fixing complement with convalescent sera.