Observations on the Minor Basic Hemoglobin Component in the Blood of Normal Individuals and Patients with Thalassemia

In a previous report (1) a second hemoglobin was described which was found at a concentration of approximately 3 per cent in the blood of normal adult individuals. It was found to resemble hemoglobin E in electrophoretic properties, but identity with this abnormal hemoglobin was not established. This same component probably had been observed by previous investigators employing the classical Tiselius procedure in occasional specimens of blood from normal persons (2, 3) and thalassemia patients (4), but had not been defined as a hemoglobin. The present report describes further properties of this hemoglobin (designated A2 in this paper) with particular reference to its constant presence in the blood of humans and