Strain specific TIMP1 protein expression analysis in homozygous B-hTIMP1 mice by ELISA. Serum was collected from wild-type mice (+/+) and homozygous B-hTIMP1 mice(H/H), and analyzed by ELISA with species-specific TIMP1 ELISA kit. Mouse TIMP1 was detectable in wild-type mice. Human TIMP1 was exclusively detectable in homozygous B-hTIMP1 mice.