Strain specific CLU expression analysis in homozygous B-hCLU mice by ELISA. Serum were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCLU mice (H/H), and analyzed by ELISA with species-specific CLU ELISA kit. Mouse CLU was detectable in wild-type mice. Human CLU was exclusively detectable in homozygous B-hCLU but not wild-type mice.