Hemoglobin

Abbreviated as Hb. A major protein in Red blood cells (RBCs) that is responsible for carrying oxygen. It is composed of four peptide chains. The three major normal hemoglobins are Hb-A ( 2 alpha chains and 2 Beta chains), Hb-A2 (2 alpha chains and 2 delta chains), and Hb-F (2 alpha chains and 2 gamma chains). The Hemoglobin value can be measured along with Hct, WBC and platelets as part of a routine CBC. Decreased hemoglobin and Hct levels are indicative of anemia. The normal ratio of hemoglobin to hematocrit is about 1:3 (e.g. Hemoglobin of 10 g/dL usually correlates with a Hematocrit of 30%).