Gene targeting strategy for B-hCRP mice. 
The exons 1-2 of mouse Crp gene that encode the full-length protein were replaced by human CRP exons 1-2 in B-hCRP mice.

Strain specific CRP expression analysis in wild-type C57BL/6 mice and homozygous B-hCRP mice by ELISA. Serum was collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCRP mice (H/H) (n=3, 6-week-old). Protein expression level of CRP was analyzed by ELISA. Mouse CRP was exclusively detectable in wild-type C57BL/6 mice. Human CRP was exclusively detectable in homozygous B-hCRP mice

Strain specific analysis of CRP mRNA expression in wild-type C57BL/6 mice and B-hCRP mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCRP mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human Crp primers. Mouse Crp mRNA was detectable only in wild-type C57BL/6 mice. Human CRP mRNA was detectable only in homozygous B-hCRP mice but not in wild-type mice.