Mean corpuscular hemoglobin
The mean corpuscular hemoglobin, or "mean cell hemoglobin" (MCH), is the average mass of hemoglobin (Hb) 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.
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 weight of the red cell is determined by the iron (as part of the hemoglobin molecule), thus MCH in picogram is the weight of one red cell. In iron deficiency anemia the cell weight becomes lighter, thus a MCH < 27pg is an indication of iron deficiency. The MCH decreases when Hb synthesis is reduced, or when RBCs are smaller than normal, such as in cases of iron-deficiency anemia. Conversion to SI-units: 1 pg of hemoglobin = 0.06207 femtomol. Normal value converted to SI-units: 1.68 – 1.92 fmol/cell.