Abstract: A source for antibodies (both IgG and IgM types) is put into an aqueous solution which includes a virucidal agent under conditions sufficient to assure substantially complete dissolution of both the antibodies and the virucidal agent and virus inactivation. Then the pH, conductivity and antibody concentration of the solution are then changed to obtain conditions sufficient to assure the precipitation of substantially all antibodies while maintaining substantially all of the virucidal agent in the supernatant solution.In preferred embodiments, using a TNBP/TWEEN virucidal agent, the original solution conductivity ranges from about 0.03 to 0.20 M MHO/CM, the pH ranges from about 4.75 to 4.85, and the protein concentration, when measured at A280, ranges from a reading of about 5 to 40. In the second precipitation step, the pH is changed to a range of about 6.0 to 7.5 and the conductivity is changed to a range of about 0.05 to 0.