{'fraction_non_alphanumeric': 0.029093931837073983, 'fraction_numerical': 0.013300083125519535, 'mean_word_length': 5.174358974358975, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Detection and Diagnosis of Hemoglobin A 2 ' by High-Performance Liquid Chromatography

The substitution of arginine for glycine confers a net positive charge gain on the δ-globin chain, which accounts for its mobility cathodal to HbA2 on alkaline electrophoresis. Because HbA2' accounts for such a small percentage of the total Hb in heterozygotes, it is difficult to detect by this method. HbA2' is easier to detect by isoelectric focusing (IEF); however, this method is not widely used as a primary screening method beyond the neonatal period, when HbA2 levels normally are low. HbA2' coelutes with HbA2 by microcolumn chromatography, and, thus, the total HbA2 level measured by this method would be expected to be accurate, although the HbA2' component would not be identified. In recent years, high-performance liquid chromatography (HPLC) has replaced alkaline electrophoresis as the primary screening method for hemoglobinopathies in many laboratories.11 HPLC offers the advantages of decreased manual labor, lower cost, and direct quantification of even minor Hb components, including HbA2. HbA2' is perhaps detected most easily by HPLC, in which it produces a minor peak in the S window.4,12