S monovette serum collection system

On admission to the hospital, in Group I after the end of preoperative IN, and then, in both groups on the eighth day after surgery, C-reactive protein and Interleukin-1α were measured. Venous blood (5.5 mL) was collected on an empty stomach from all patients after overnight rest using the S-Monovette^® serum collection system (Sarstedt, Germany). Immediately after collection, the blood was centrifuged at 1500× g for 10 min at +4 °C (MPW 351, MPW Med. Instruments, Warsaw, Poland) to separate serum from erythrocytes. The top layer (serum) was then collected. Approximately 0.5 M butylated hydroxytoluene (20 μL/2 mL plasma or serum) was added to prevent sample oxidation. Until the selected parameters of inflammation were determined, all samples were stored at −80 °C.
Interleukins were assayed using a customized Bio-Plex Pro Human Cytokine Screening Panel, 48-Plex (#12007283) (Bio-Rad Laboratories, Life Science Group, Hercules, CA, USA).