Figure 2: Results from the calibrator-normalized relative quantization analysis of the differentiation markers RUNX2, ALP and OC with real-time qRT-PCR. Summarized osteoblasts grown with differentiation factors showed a higher level of all three differentiation markers. RUNX2 and OC showed a time dependent gene expression, while the ALP gene was high expressed already at day 6. In agreement with earlier reports, an increased time dependent differentiation was also induced in control cells (grown without differentiation factors). This differentiation could be explained by the osteoblasts' ability to spontaneous differentiate as result of high confluence in growth chambers.