S monovette edta k3 tube

Blood was collected on an empty stomach, during routine examinations in the case of adolescents from the control group, and for the study groups: during admission to the Pediatric and Nephrology Clinic of the Medical University of Bialystok. Blood was collected in the amount of 10 mL using an S-Monovette^® EDTA K3 tube (Sarstedt, Nümbrecht, Germany). After collection, the blood was centrifuged (3000 g, 10 min, 4 °C). No hemolysis was observed in any of the obtained plasma samples. Blood cell mass was rinsed 3 times with 0.9% NaCl, and then underwent osmotic lysis using 50 mM cold phosphate buffer (pH 7.4) 1:9 (v/v) [17 (link)]. To prevent sample oxidation, 0.5 M BHT (Sigma-Aldrich, Saint Louis, MO, USA; 10 µl/ml blood) was added to the plasma and red blood cell lysate [17 (link)]. Plasma and blood lysate were frozen (–82 °C). The samples were stored deep-frozen for no longer than 6 months.

Blood was collected at fasting, either at the admission of a patient to the hospital or during routine tests in case of control subjects. Blood was collected at 5 mL using an S-Monovette EDTA K3 tube (Sarstedt, Nümbrecht, Germany). The samples were then centrifuged (3000 × g, 10 min, 4 °C). No hemolysis was observed in any of the obtained plasma samples. To prevent sample oxidation, 0.5 M Butylated hydroxytoluene BHT (Sigma-Aldrich, Saint Louis, MO, USA; 10 µL/mL blood) was added [28 (link)]. Plasma was frozen (−82 °C). The samples were stored deep-frozen for no longer than 6 months.

Blood was collected on an empty stomach on the same day as, but prior to, the patient's examination and saliva collection. 7.5 mL of venous blood was collected in a S-Monovette® EDTA K3 tube (Sarstedt, Nümbrecht, Germany). Under laboratory conditions, the samples were centrifuged in order to separate the plasma from erythrocytes (1500 × g; 4°C, 10 minutes). Erythrocytes were rinsed three times with 0.9% cold NaCl (v/v) and then haemolysed by adding 50 mM cold phosphate buffer (pH 7.4) 1 : 9 (v/v) [28 (link)]. To prevent sample oxidation, 0.5 M BHT (Sigma-Aldrich, Saint Louis, MO, USA; 10 μL/mL blood) was added to the blood [28 (link)]. The samples with signs of undesired haemolysis were excluded from the study. All samples were stored at -82°C (but not longer than six months).