Objective  To construct eukaryotic expression bicistron plasmid vector pcDNA3.1-hOPG

and to detect the expression of the plasmid in vitro.   Methods  hOPG cDNA fragment was extracted from plasmid MGC:29565

amplified by PCR

and inserted into pcDNA3.1(-) vector

then identified by restriction endonuclease digestion and nucleotide sequencing. C

2

C

12

cells were transfected with the plasmid using Lipofectamine 2000. The expression of OPG protein was detected by immunohistochemistry techniques and bone wafer pit assay.   Results  The constructed recombinant plasmid contained the sequence of hOPG gene. After transfection with the plasmid

active OPG protein could be expressed in C

2

C

12

c

ells.   Conclusion  The constructed eukaryotic expression bicistron plasmid vector pcDNA3.1-hOPG can express OPG in vitro

which is the basis for further study on the treatment of bone absorption caused by abnormal activity of osteoclasts.