AbstractB16 melanoma was studied in syngeneic C57BL/6J mice as a therapeutic model of melanoma. The irregular behavior of tumor after trochar passage was eliminated by serial intraperitoneal passage, but abundant melanin production was maintained. Mean viability of dispersed suspensions was 56%. Median survival time after injection of 107cells intraperitoneally was 11‐16 days (average 13.20).In vivodoubling time was estimated at 3.24 days. Tenfold increase time was approximately 10.75 days. Preliminary studies with rabbit antiserum demonstrated possible enhancement after incubation with tumorin vitro, and a possible therapeutic effect after administrationin viv