Strain specific CSF1R expression analysis in heterozygous B-hCSF1R mice by flow cytometry. Blood were collected from WT and heterozygous B-hCSF1R (H/+) mice, and analyzed by flow cytometry with species-specific anti-CSF1R antibody. Mouse CSF1R was detectable in WT and heterozygous B-hCSF1R mice. Human CSF1R was exclusively detectable in heterozygous B-hCSF1R mice but not in WT mice.