Hemoglobin

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). Hemoglobin can be measured along with the Hematocrit, WBC and platelets as part of a routine CBC (complete blood count). Decreased hemoglobin and Hct levels are indicative of anemia.