Derived from the same tumor a RAW 309F.1.1 (ATCC CCL 51); negative for surface immunoglobulin (sIg-) Thy-1.2(Thy-1.2-) and Ia(Ia-); the cells will pinocytose neutral red and phagocytose latex beads and zymosan; they will also lyse antibody coated sheep erythrocytes; tested and found negative for ectromelia virus (mousepox)