. The resulting blood was collected in a clotted blood septum and left at 4 °C for approximately 2 hours to stratify the blood, and was taken a blood sample was centrifuged at a speed of 3,000 xg. for 10 min at a temperature of 4 °C. Serum was stored separately in a 0.6 mL centrifuge tube and stored at -80 °C.