1. Antisera to hemoglobin solutions obtained from normal adult, cord blood and sickle cell anemia erythrocytes have been prepared by immunizing rabbits with adjuvant mixtures. Furthermore, anti F hemoglobin sera have been similarly prepared by using purified fetal hemoglobin. A species specific anti guinea pig hemoglobin serum was also developed.
2. Although anti F hemoglobin sera appear to be specific for fetal hemoglobin, no such immunologic specificity could be detected between anti A and anti SCA sera obtained from rabbits.
3. It is suggested that sera prepared by using hemoglobin solutions obtained from normal and sickle cell anemia erythrocytes may contain anti F antibodies in addition to anti A and anti S precipitins and that fetal hemoglobin may be present in many human adult blood specimens.