Figure 2.
Standard operating procedure (SOP) for blood handling in the Danish Rheumatologic Biobank.31 Peripheral blood is collected in one EDTA tube, two serum tubes and one PAXgene blood RNA tube. Serum tubes coagulate at room temperature for 30 min to 2 hours. From the EDTA tube, 1.5 mL whole blood is isolated. EDTA and serum tubes are centrifuged at 2000xg and 4°C for 10 min. EDTA plasma (2×2 mL), EDTA buffy coat and serum (4×2 mL) are isolated. Processed blood samples are stored at ≤−20° C. PAXgene blood RNA tubes are kept at room temperature for 2–72 hours, then frozen at −20°C for 24–72 hours and stored at −80°C.