Red blood cell oxygen has been released the resulting deoxyhemoglobin is of a dark red burgundy color. However, blood can appear bluish when seen through the vessel wall and skin. Pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a very high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a saturation reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. Having oxygen-carrying proteins inside specialized cells (as opposed to oxygen carriers
Blood donation in England and each donation usually gives two or three adult doses. One adult dose of platelets would otherwise require four whole blood donations. Blood is made in the bone marrow. It is composed of red blood cells, platelets, plasma and white blood cells, collectively referred to as blood components. Donations given at regular blood donation sessions are referred to as "Whole Blood". Platelets are very small cells. They work with the clotting factors in plasma to form a mesh "plug" to stop or prevent bleeding. Plasma is the fluid part of the blood. It contains protein, salts and clotting factors. White