BMPC-rich elutriation fractions (n = 4) cultured in DMEM-20% FCS with varying concentrations of BMP2 for 5 days. Supernatants were collected and analyzed for alkaline phosphatase activity (AP; the release of pNP is a measure of AP activity). The lowest concentration of BMP2 (1 ng/ml) caused a significant increase in AP activity. **P > 0.004.
Zvaifler et al. Arthritis Res 2000 2:477 doi:10.1186/ar130