Hemoglobin F, Red Cell Distribution, Blood
Method Description Describes how the test is performed and provides a method-specific reference
This assay uses a flow cytometric method with a monoclonal antibody to hemoglobin F (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 hemoglobinonly, 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 showed both Hb A and Hb F peaks, corresponding to the heterocellular pattern of the K-B method. In patients with Hb S/hereditary persistence of fetal hemoglobin, a single peak was observed in contrast to patients with homozygous S in which 2 peaks were observed. (Hoyer JD, Penz CS, Fairbanks VF, Katzmann JA: A flow cytometric method for measurement of Hb F in red cells: applications in the evaluation of hereditary persistence of fetal hemoglobin [HPFH] and other conditions with elevated Hb F levels. Blood 1998;92:40b)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; Continuously