A comparison of the macrophage electrophoretic mobility test and the leukocyte migration inhibition test in the detection of histocompatibility antigens on tumor cells.

Lymph node cells from mice sensitized by rejection of skin allografts were incubated in vitro with tumor cells carrying the sensitizing alloantigens. Products of the lymphocyte--antigen interaction released into the culture medium were simultaneously assessed by the macrophage electrophoretic mobility test and the leukocyte migration inhibition assay. Both macrophage slowing factor (MSF) and a factor which inhibited leukocyte migration (LIF) were produced. The release of both factors was detectable after comparable periods of incubation; their production was transient and ceased within 24 hours after it started.