Classifying Human Haptoglobin Phenotypes on Native‐PAGE Using a Modified Coomassie Brilliant Blue R 250 Staining

There are three types of human Haptoglobin, Hp 1-1, Hp 2-1, and Hp 2-2, each characterized by a distinct combination of the two α chains of the holoprotein. A modified Coomassie Brilliant Blue R 250 (mCBB-R250) staining method for detecting the phenotypes of human blood haptoglobin molecules is presented. Addition of excess hemoglobin to the sample allowed specific formation of different haptoglobin-hemoglobin complexes, which, in turn can be separated into distinctive migration pattern on native-PAGE and stained by CBB-R250. The typing results are consistent with that using Western blotting. In comparison to the existing methods for haptoglobin typing, our method is comparable in accuracy, and is easier to carry out. The results on typing of 29 plasma samples from Taipei Blood Center were also presented.