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
Hemoglobin Hopkins-2 carboxyl group of the amino acid forms a hydrogen bond with phenolix hydroxyl, which in turn stabilizes the structure of the molecule and increases oxygen affinity. Ho-2 hemoglobin has high levels of oxygen, which replaces the lack of oxygen within red blood cells. Ho-2 is similar to Hemoglobin A, which is normal hemoglobin and also contains two α-chains. This provides an explanation as to how the Hopkins-2 variant of hemoglobin is related to the symptoms of sickle cell. Hopkins-2 can also interact specifically with Hemoglobin S. Hemoglobin S is the most common abnormal hemoglobin variant. Hemoglobin S is the variant