Strain specific PSGL-1 expression analysis in homozygous B-hPSGL-1 mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6 mice (+/+)  and homozygous B-hPSGL-1 mice (H/H), and analyzed by flow cytometry with species-specific anti-PSGL-1 antibody. Mouse PSGL-1 was detectable in wild-type C57BL/6 mice (+/+). Human PSGL-1 was exclusively detectable in homozygous B-hPSGL-1 mice (H/H) but not wild-type C57BL/6 mice (+/+).