Urea nitrogen colorimetric detection kit

Blood was collected every 28 d into 10.0 mL, 16 × 100 mm BD Vacutainer serum blood collection tubes. After coagulation, blood was cooled at 4 °C, and serum was extracted the next day after a 15 min centrifugation at a speed of 100 xg. Serum was stored at −20 °C for future analyses. Blood urea nitrogen was determined using a commercially available BUN detection kit (Urea Nitrogen Colorimetric Detection Kit, Invitrogen, Carlsbad, CA) following the manufacturer’s specifications. Results of the BUN detection assays were analyzed on a BioTek Synergy H1 plate reader (BioTek, Winooski, VT) using the program Gen5 version 2.09. Intra-assay CV: 3.84%. Inter-assay CV: 1.69%.

This study was conducted with approval by the Human Ethics Committee of Jingzhou Central Hospital, the Second Clinical Medical College of Yangtze University. Kidney tissues were collected from 30 sepsis patients and 30 healthy volunteers at Jingzhou Central Hospital, the Second Clinical Medical College of Yangtze University. The inclusion criteria were: all patients with clear evidence of infection or highly suspected infection accompanied by at least 2 signs of SIRS and complete and reliable clinical data. The exclusion criteria were: drugs previously taken had renal toxicity; previous history of glomerulonephritis, nephrotic syndrome, end-stage nephropathy, renal cancer, or renal transplantation; and a lactating or pregnant woman. None of the patients or volunteers had received any preoperative treatments. Moreover, written informed consent was signed from each participant. All kidney tissues were promptly snap-frozen and then transferred to a −80°C freezer for long-term preservation. In addition, venous blood was collected and stored at −80°C after centrifugation to assess renal function indicators – blood urea nitrogen (BUN) and serum creatinine – with a Urea Nitrogen Colorimetric Detection Kit (Invitrogen, Carlsbad, CA, USA) and Creatinine Urinary Detection Kit (Invitrogen).