Fetal Hemoglobin-containing Erythrocytes I. Counts of Cells Stained by the Acid Elution Method Compared with Alkali Denaturation Measurements

The quantitative study of peripheral smears for red cells containing fetal hemoglobin ("F-containing cells") by the acid elution method is a useful and dependable screening test. Findings with this approach were compared with fetal hemoglobin assay by alkali-denaturation in a series of 19 normal subjects and 63 subjects with an assortment of blood disturbances. The results of the two methods had a correlation of +.79, suggesting a reliable but far from perfect identity between the methods. The acid elution method tended to give higher readings, and seemed more sensitive for recognizing individuals with slight increases in red cell fetal hemoglobin as occurs in thalassemia minor.