Analysis of MSU crystal–induced DNA externalization. (A–D) Nuclei of WT and Hck^−/−Fgr^−/−Lyn^−/− mouse neutrophils (A and B), or of WT neutrophils treated with vehicle or 100 nM dasatinib (C and D) were stained with 0.5 μg/ml Hoechst dye followed by addition of 0.2 mg/ml MSU crystals along with 50 nM Sytox-Green DNA to visualize extracellular DNA. Panels A and C are representative images (scale bar: 200 µm), and panels B and D show the quantification of the externalized DNA area as mean and SEM from four (A and B) or three (C and D) independent experiments. Two-way ANOVA genotype × stimulus or inhibitor × stimulus interaction analysis; n.s., not significant. See the text for actual P values.