Tentative identification of hemoglobin variants in the Bio-Rad VARIANT II Hb A 1C method

Abstract

Objective: To evaluate if peak characteristics, the retention time, and percentage of total hemoglobin of an unknown peak on the Bio-Rad VARIANT II Hb A 1c method may be used to establish a tentative identification of hemoglobin variants. Method: The peak characteristics, retention time, and percentage of total hemoglobin obtained on abnormal peaks found on the Bio-Rad VARIANT II Hb A 1c method were tabulated and evaluated against the identification of the hemoglobin variant established by the Bio-Rad β thalassemia HPLC method and hemoglobin electrophoresis at both acid and alkaline pH. Results: Some hemoglobin variants show specific peak characteristics, retention times, and percentage of total hemoglobin on the Bio-Rad VARIANT II Hb A 1c method that allows for tentative identification of the hemoglobin variant. The retention times and percentage of hemoglobin variant for the common hemoglobin variants E, D, S, and C obtained on the Bio-Rad VARIANT II Hb A 1c method are tabulated below. Hemoglobin variant n Mean retention time (min) (1 SD) Mean percentage of total hemoglobin (1 SD) E 25 1.906 (0.009) 34.32 (1.96) D 30 1.942 (0.007) 43.20 (2.24) S 87 1.966 (0.007) 41.53 (3.14) C 22 2.017 (0.02) 37.65 (3.71) Conclusion: Peak characteristics, retention times, and percentage of hemoglobin variant may be used to establish the presence of a hemoglobin variant and to provide a tentative identification of some hemoglobin variants on the Bio-Rad VARIANT II Hb A 1c method.