Haemoglobin extraction from bovine blood. The red blood cell (RBC) lysis approach was adopted for Hb extraction. Whole bovine blood from an Auckland meat processor, which contains plasma (55 % of the total blood), white blood cells and platelets (less than 1 % of the total blood) and RBCs (45 % of the total blood), was treated with 10 % sodium citrate and subjected to centrifugation at 3500 rpm for 15 min at 4 °C. The RBC layer was collected and treated with equal volumes of 0.1 % NaCl as a hypotonic solution for 1 h at 4 °C to rupture the RBCs. Next, centrifugation was performed at 3500 rpm for 30 min at 4 °C to remove the RBC membrane debris.