Agglutinating Action of Heat-Inactivated Passage A Mouse Leukemia Filtrates on Mouse Red Blood Cells.

Abstract

Heated (55[degree]C, 1/2 hour) passage A leukemic filtrates had an agglutinating effect on mouse erythrocytes in dilutions up to 1:160, occasionally higher. Fresh filtrates did not agglutinate. The agglutinin could be separated from leukemic agent by ultracentrifugation. Tests were routinely done at 4[degree]C but could also be carried out at room temperature; the agglutinin did not elute. Heated (55[degree]C, 1/2 hour) filtrates from spontaneous Ak leukemias agglutinated only in some instances, and in higher concentrations. Whether the agglutinating potency of some Ak leukemic filtrates is related to their ability to induce leukemia, remains to be determined. Fresh or heated filtrates from pooled normal mouse organs agglutinated only in some instances, and in higher concentrations. The agglutinating potency of heated leukemic passage A filtrates could be inhibited by specific rabbit immune serum to 1:128 dilution. Normal rabbit serum had an inhibiting effect only in 1:4 to 1:16 dilutions.