ALP and TRAP activities in osteoblast differentiation. (A) ALP activities during osteoblast differentiation. There was significantly increased ALP activity in mononucleated cells at days 10 and 14 of differentiation, while MC3T3-E1 cells showed significant increases at days 7, 10 and 14 of differentiation. (B) TRAP activities during osteoblast differentiation. There were significant increases of TRAP activity in mononucleated cells at days 5, 10 and 14 of osteoblast differentiation. The TRAP activity in MC3T3-E1 remains constant and similar to control activity. Results are presented as mean ± SD (n = 3). The * and § indicate significant difference (p < 0.05) of mononucleated cells and MC3T3-E1 respectively as compared with day 0.