Abstract
1. It could be demonstrated that of the three tested types of human hemoglobin—N (normal adult), S (sickle cell) and F (fetal)—only the reduced S compound shows tactoid and gel formation in sufficiently concentrated solutions. These physico-chemical phenomena may be used for the qualitative identification of S hemoglobin.
2. The alkali resistant hemoglobin fraction, present in sickle cell anemia erythrocytes (but not in trait red cells), was concentrated in purified form. No tactoid or gel formation could be elicited. Therefore, this alkali resistant pigment does not appear to be a variant of S hemoglobin. It seems probable that sickle cell anemia erythrocytes contain two separate types of pathologic hemoglobin (S and F) which are not directly related to each other.
