The Complement-Fixing Antigen of Rubella Virus.

Abstract
Summary A complement-fixing antigen for rubella virus has been produced by concentration of infected RK-13 cell culture fluids 100-fold by dialysis against polyethylene glycol. The antigen was shown to be separable from the intact viral particle by centrifugation (soluble antigen), and could be rendered non-infectious by ether treatment without undergoing a change in specific reactivity. The complement fixation test was found to be comparable to the neutralization test for detecting significant increases in antibody level in rubella virus infections. Individuals showing significant rises in antibody titer to myxo-virus antigens or Mycoplasma pneumoniae did not show antibody rises with the rubella complement-fixing antigen.