Serum (HS) was collected from each animal one wk before BMSC isolation. Animals were sedated with detomidine hydrochloride (0.02 mg/kg btw) intravenously. Approximately 500 mL of blood was taken and and stored in 50 mL tubes. Blood was incubated at room temperature for 2 to 4 h to allow clotting. The blood was refrigerated at 4°C for 10 to 12 h. Next, the tubes were centrifuged at 1,800 × g for 30 min at 4°C. In a sterile environment, the serum was transferred by gently pipetting into a new tube. The serum was filtered through 0.22 μm pores. Next, the serum was frozen at -20°C for 12 h. The next d, the serum was thawed to room temperature, heat inactivated by incubating at 56°C for 30 min, filtered through 0.22 μm pores, and stored at 4°C for immediate use or -20°C for future use in cell culture experiments [13].