Forward and side scatter profiles of peritoneal cells. Forward and side scatter analysis (see the Materials and Methods) was performed on peritoneal cells taken before (A) and at various times after (B through D; 16, 72, and 96 hours, respectively) TM injection. On the basis of surface marker expression (see Table 1 and associated text), three regions (R1, R2, and R3) were defined for subsequent studies: R1, “macrophage” region at t = 0; R2, “lymphocyte” region at t = 0; and R3, “neutrophil” region after TM injection. Constant instrument settings were used. The data are from a representative experiment (8 mice) that was repeated 8 times.