Strain specific CD8 expression analysis in wild type C57BL/6 mice and homozygous humanized B-hCD8 mice by flow cytometry. Blood were collected from wild type C57BL/6 mice (+/+) and homozygous B-hCD8 mice (H/H), respectively, and analyzed by flow cytometry with species-specific anti-hCD8a, anti-hCD8b, anti-mCD8a antibodies. hCD8a and hCD8b were exclusively detectable in homozygous B-hCD8 mice(A). mCD8a was not detectable in homozygous B-hCD8 mice(B).