Alizarin Red S staining of hABMMSCs. At 24 h after third generation log-phase hABMMSCs were infected with the pCMV-MCS-EGFP (Con) or pAdCMV-SEMA3A-MCS-EGFP (Sema3A) vector, the cells were seeded in 6-well plates and grown in osteogenesis-inducing media. Following incubation for 7, 10, 14 and 21 days, Alizarin Red S staining was performed (n=3 per experiment). Sema3A, semaphorin 3A; Con, control; hABMMSCs, human alveolar bone marrow mesenchymal stem cells.