After a 6-day osteogenic induction, the murineMC3T3-E1 cellswere
incubated using serum-free medium,which contained Rb2 and/or H2O2
for 2 days. The cells were stained using the BCIP/NBT alkaline phosphatase
color development kit according to themanufacturer's instructions.
To evaluate the ALP activity, the cell monolayer was lysed using the cell
lysis buffer. Subsequently, the lysate was centrifuged at 10,000 g for
5 min. The clear supernatant was used to measure the ALP activity,
which was determined employing the ALP activity assay kit. The total
protein consistencies were determined using the Bradford protein
assay method. The ALP activity was normalized to total protein, which
was measured using the Bradford protein assay method.