Method Description

This assay uses a flow cytometric method with a monoclonal antibody to hemoglobin (Hb) F. Specimens are analyzed by single-color flow cytometry using fluorescein anti-Hb F. In normal adults, a single peak is seen with minimal fluorescence, which corresponds to Hb A. In neonates, a single peak with bright fluorescence is seen, which corresponds to Hb F. In cases of hereditary persistence of fetal Hb (HPFH) only, a single peak is observed, which has a fluorescence intensity intermediate between the normal Hb A and Hb F peaks. This pattern corresponds to the homocellular (pancellular) pattern obtained by the Kleihauer-Betke (K-B) method. In contrast, specimens from infants, transfused neonates, and cases of beta-thalassemia or delta/beta-thalassemia show both Hb A and Hb F peaks, corresponding to the heterocellular pattern of the K-B method. In patients with Hb S/HPFH, a single peak was observed in contrast to patients with homozygous S in which 2 peaks were observed.(Package insert: Invitrogen Fetal Hemoglobin Test Kit with FITC-conjugated Monoclonal Antibody Directed to HbF. Life Technologies Corporation; MAN 0003641, Rev 3.02, 11/21/2019)