Detection of infectious centers in C57BL/Ka lymphoid cell populations infected in vitro by the radiation leukemia virus.

The cocultivation of nonproducer lymphoma cells derived from a radiation-induced lymphoma of the C57BL/Ka mouse with cultures of lymphoid cell populations from the thymus, spleen, and marrow of the same strain 48 hr after their infection by the C57BL/Ka leukemia viruses permits the detection of infectious centers in these cultures. A quantitative assay is described which allows the estimation in lymphoid cell subpopulations of the numbers of target cells susceptible to productive infection by the thymotropic and leukemogenic viruses of C57BL/Ka mice in vitro. This assay should greatly facilitate the identification and characterization of such target cells.