Mixed infiltrating SR/CR leukocytes kill S180 cells via necrosis. SR/CR mice were challenged i.p. with 10⁷ S180 cells, and the responding leukocytes and S180 cells removed from the peritoneal cavity after 1 h. The killing of S180 cells by SR/CR leukocytes was recorded with time lapse video phase-contrast microscopy for 24 h in an incubated chamber at 39°C with 5% CO₂. In this field, a leukocyte (arrowhead) targets an S180 cell (arrow) (A), migrates toward the S180 cell (B), and results in the swelling and rupture of the S180 cell (C, D). The figure shown here is representative of at least 3 separate experiments.