Secreted Alkaline Phosphatase (SEAP) Analysis
Secreted alkaline phosphatase activity was analyzed by GreatEscape SEAP kit according to the manufacturer's instruction. Briefly, medium was diluted in the dilution buffer and heated to 65°C to inactivate endogenous phosphatases then incubated with the substrate for 30 minutes. The chemiluminence signal was recorded using a luminometer.