Iodine-125-labeled antibody to viral antigens: binding to the surface of virus-infected cells.

The specific binding of iodine-125-labeled antibody to viral antigens can be used to detect newly synthesized viral antigens and determine the time of appearance of these antigens on the surface of infected cells. Incubation of infected cells with unlabeled antibody to viral antigens specifically blocks the attachment of labeled antibody, and by this inhibition technique the titer of unlabeled antibody to viral antigens can be calculated. The attachment of the labeled antibody to virus-infected cells offers an objective and sensitive method of detecting viral antigens and measuring antibody to virus.