Ethylene diamine tetraacetic acid (edta)

Blood was collected into EDTA-containing tubes ( $1.6$ mg/mL EDTA, SARSTEDT, Nümbrecht, Germany) with informed consent from three healthy male voluntary donors (age 28–31 years). It was centrifuged for 5 min at 3000× g to separate RBCs and plasma. Sedimented RBCs were washed three times with a phosphate-buffered saline solution (Gibco PBS, Fisher Scientific, Schwerte, Germany). Finally, a hematocrit concentration of $1\%\mathrm{Ht}$ was adjusted in a PBS solution that contained $1$ g/L bovine serum albumin (BSA, Sigma-Aldrich, Taufkirchen, Germany). The viscosity of the PBS/BSA solutions at $20°$ C was approximately $1.2$ mPa s [56 (link)], similar to the viscosity of human blood plasma. Since we do not observe significant inter-individual variations in the results, data were averaged between the three donors.
Blood withdrawal, sample preparation, and microfluidic experiments were performed according to the guidelines of the Declaration of Helsinki and approved by the ethics committee of the “Ärztekammer des Saarlandes” (permission number 51/18).

Venous blood samples were obtained from the antecubital vein into vacutainer tubes containing EDTA (Sarstedt, Leicester, UK). Plasma was separated after centrifugation at 1200 × g for 30 min at 4°C within 60 min of collection and immediately transferred into 7 mL Kimble scintillation vials (Kinesis, St. Neots, UK) and stored as 2 mL aliquots at −80°C prior to plasma lipid extraction and quantification.

Blood was collected from the jugular vein of 392 cattle directly into blood collection tubes containing EDTA (Sarstedt, Nürnbrecht, Germany). The collected blood was centrifuged at 3000× rpm for 15 min. The upper layer containing plasma and the buffy coat was collected separately in 1.5 mL cryotubes. NAPA was added to the buffy coat resulting in a 1:4 final dilution. The PCV of each blood sample was measured following centrifugation in heparinised haematocrit capillary tubes at 12,000× rpm for 5 min (haematocrit centrifuge from Hawksley, UK). An animal with a PCV value below 25% was considered to be anaemic [11 (link)].

Blood was collected with capillary tubes coated with EDTA (Sarstedt) and the blood was centrifuged to collect plasma from overnight-fasted mice, as well as 15 and 30 min after glucose injection. Five to ten microliters of plasma were analyzed by ELISA to measure insulin and c-peptide (ALPCO), as well as proinsulin (Mercodia).

Blood of 6 healthy donors (4 men and 2 women, 25 to 51 years old) was used for experiments on the influence of hemin, different pH, UV radiation, and temperature change of RBC suspension in buffer solution. Blood sampling (150 μL) was performed in microvettes with EDTA (Sarstedt AG & Co., Numbrecht, Germany) during a prophylactic examination. We received informed consent from each donor.
For the experiments of blood storage, we used leukoreduced packed red blood cells. The pRBCs units were stored for 40 days in CPD/SAGM solution at +4 °C. Hematocrit was 60–65%. A single unit of pRBCs was 450 mL in volume. The pRBC units were obtained from Moscow blood transfusion centers. Two units of two blood groups were used in the study: O (I), A (II). On the experimental day, the sample was taken from pRBCs units without violating hermetical seal and integrity.
Research protocol was approved by the Ethics Committee of the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russian Federation (protocol no. 2/20 of 10 June 2020).
To obtain smears for atomic force microscope scanning, 10 μL of the sample was dropped onto a slide. The RBC monolayer was prepared using a V-Sampler device (Vision, Vienna, Austria). The sample was air-dried before scanning by AFM.

Trunk blood was collected at the moment of decapitation into a 1.3 ml Eppendorf tube coated with EDTA (Sarstedt, Vantaa, Finland). TRIzol LS reagent (Thermo Fisher Scientific, MA, USA) was immediately added (3:1 ratio of reagent to blood) and the samples were stored at -80°C for a maximum of two weeks prior to RNA extraction [84 (link)].