In vivo peritonitis model. (A) Peritonitis was induced in WT recipients and Srf WT, and KO neutrophils labeled with membrane dyes of 2 different colors were simultaneously injected intravenously and allowed to localize to tissues. PB, BM, and lavage fluid were harvested and percentages of donor WT vs KO neutrophils determined by flow cytometry detecting differential membrane staining (B-C). The experiment shown in panel B is representative of 4 independent experiments with n = 4 recipient mice of WT and KO neutrophils from 2 donors per experiment. Membrane dyes were alternated for WT and KO cells; **P < .005. (C) Primary flow data from 1 recipient showing donor KO and WT neutrophil distribution.