Strain specific PDGFB expression analysis in homozygous B-hPDGFB mice by ELISA. Serum was collected from wild-type mice (+/+) and homozygous B-hPDGFB mice (H/H) and analyzed by ELISA with PDGF BB ELISA kit. Mouse PDGF BB was exclusively detectable in wild-type mice. Human PDGF BB was both detectable in wild-type mice and homozygous B-hPDGFB mice, as the kit is crossly reactive with human and mouse PDGF BB.