Figure 6: RT-PCR analysis of cell cultures between LIPUS treatment and static culture for 2 weeks. Expression of genes associated with the osteoblastic differentiation was examined using real time PCR to investigate the effect of LIPUS treatment on gene expression (a). Expression levels (b) of CD29 (A), CD44 (B), COL1 (C), and OCN (D) at 2 weeks were significantly higher in LIPUS treatment. Stimulation groups exposed during 10 min/day at 20% duty cycle (in CD44) or 50% duty cycle (in OCN) were significantly different ( ) among groups.