[Soluble expression, purification of bone morphogenetic protein-2 fragment and its antibody preparation]

The bone morphogenetic protein-2 (BMP-2) fragment (BMP-2omega, 606-846bp) cDNA was amplified from total RNA of SAOS-2 cells by using RT-PCR. The PCR product was then inserted into pET-28a (+) vector for constructing the expression plasmid that would be used to transform the host cell BL21(DE3). After IPTG inducing under different conditions, this BMP-2w protein could be expressed in high level as a soluble form, and purified by chelating column (Ni-NTA). Polyclonal antibody was made by immunizing mice with using purified protein, and the antiserum titer generated was 1: 6400 that was measured by ELISA. Western blot result showed that this antibody could bind to BMP-2 protein specifically. Above research result set up the basis for studying on the treatment of osteosarcoma.