Strain specific analysis of CD3E gene expression in wild type (WT) mice and B-hCD3E/hHER2 mice by RT-PCR. Mouse Cd3e mRNA was detectable only in spleen of WT mice (+/+). Human CD3E mRNA was detectable only in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+). 

Strain specific analysis of HER2 gene expression in wild type (WT) mice and B-hCD3E/hHER2 mice by RT-PCR. Mouse Erbb2 mRNA was detectable only in liver of WT mice (+/+). Human ERBB2 mRNA was detectable only in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+). 

Strain specific CD3E expression analysis in homozygous B-hCD3E/hHER2 mice by flow cytometry. Splenocytes were collected from wild type (WT) mice (+/+) and homozygous B-hCD3E/hHER2 mice (H/H;H/H), and analyzed by flow cytometry with species-specific anti-CD3E antibody. Mouse CD3E was detectable in WT mice (+/+). Human CD3E was exclusively detectable in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+).

Immunohistochemical (IHC) analysis of HER2 expression in homozygous B-hCD3E/hHER2 mice. The mammary gland tissues were collected from WT and homozygous B-hHER2 mice (H/H; H/H) and analyzed by IHC with anti-Her2 antibody. HER2 was detectable in WT mice and homozygous B-hHER2 mice due to the cross-reactivity of the antibody. The arrow indicates tissue cells with positive HER2 staining (brown).