An isoelectricfocusing method to detect hemoglobin variants in newborn blood samples including the beta-thalassemias

An isoelectricfocusing method has been developed to enable large scale screening of newborn blood for hemoglobinopathies. The method utilizes a thin layer agarose gel containing carrier ampholytes in the pH range 6-8. The gradient is non linear allowing increased resolution in the pH region 6.8-7.8 where most hemoglobin variants are isoelectric. The increased resolution between Hb A and Hb Fac enables screening for beta-thalassemia by densitometric analysis. By calculating the ratio of Hb A/Hb Fac or Hb F/Hb A it is possible to detect newborns heterozygous for beta(+)- or beta(0)-thalassemia. Structural variants, unresolved by other electrophoretic methods, are easily detected. Seventy-two samples can be analyzed on a single gel in 90 minutes. Traces of hemoglobin variants can be detected by a heme-specific stain requiring no destain step.