B2M and HLA-A3.1 expression analysis in homozygous B-NDG hB2M/HLA-A3.1 mice by flow cytometry. Splenocytes were collected from B-NDG mice (+/+) and homozygous B-NDG hB2M/HLA-A3.1 mice (H/H), and analyzed by flow cytometry with strain specific antibodies. Mouse B2M was detectable in B-NDG mice but not in B-NDG hB2M/HLA-A3.1 mice. Human B2M and HLA-A3 were exclusively detectable in homozygous B-NDG hB2M/HLA-A3.1 mice but not in B-NDG mice.