Hemoglobin by molecules such as carbon monoxide (for example, from tobacco smoking, exhaust gas, and incomplete combustion in furnaces). CO competes with oxygen at the heme binding site. Hemoglobin's binding affinity for CO is 250 times greater than its affinity for oxygen, meaning that small amounts of CO dramatically reduce hemoglobin's ability to transport oxygen. Since carbon monoxide is a colorless, odorless and tasteless gas, and poses a potentially fatal threat, carbon monoxide detectors have become commercially available to warn of dangerous levels in residences. When hemoglobin combines with CO, it forms a very bright red compound called carboxyhemoglobin, which may
Mean corpuscular hemoglobin Mean corpuscular hemoglobin The mean corpuscular hemoglobin , or "mean cell hemoglobin" (MCH), is the average mass of hemoglobin (Hg) per red blood cell (RBC) in a sample of blood. It is reported as part of a standard complete blood count. MCH value is diminished in hypochromic anemias. It is calculated by dividing the total mass of hemoglobin by the number of red blood cells in a volume of blood. MCH=(Hgb*10)/RBC A normal MCH value in humans is 27 to 31 picograms/cell. The amount of hemoglobin per RBC depends on hemoglobin synthesis and the size of the RBC. The MCH