Specificity of heteroantisera developed against purified populations of intact murine ovarian carcinoma cells.

Antisera were raised in New Zealand White rabbits against purified populations of murine ovarian carcinoma (MOT) cells that were freed from contaminating host leukocytes and erythrocytes. In contrast to other antisera raised against this tumor, heteroantisera from rabbits immunized with purified tumor cell suspensions consistently retained antitumor activity after exhaustive absorption with syngeneic (C3HeB/FeJ) adult and fetal tissues. Absorbed antisera inhibited tumor growth in vivo and reacted with MOT cells in vitro as judged by indirect immunofluorescence, binding of staphylococcal protein A, and complement-mediated cytotoxicity. Appropriately absorbed antisera failed to bind to fetal tissues or to adult spleen, ovary, and kidney cells. Antisera with similar specificity could be obtained with the use of populations purified on a fluorescence-activated cell sorter or on discontinuous rabbit serum albumin gradients. Optimal titers against tumor were raised with multiple injections of 5 x 10(5) gradient-purified MOT cells.