Which HbA1c method is described as the preferred method for measurement?

• A. Affinity chromatography
• B. HPLC
• C. Immunoassay
• D. Gel filtration

Answer: (A)

HbA1c is about how much of the hemoglobin in a blood sample has glucose molecules attached. To measure it, you need to separate the glycated Hb from the non-glycated Hb and express that glycated portion as a percentage of total Hb. In boronate (affinity) chromatography, boronic acid groups on the column bind to the cis-diol groups of the glucose moieties on glycated hemoglobin. This makes the assay capture the glycated forms (including HbA1c) and then you quantify them relative to the total Hb. Because this approach targets the sugar modification itself rather than a specific protein sequence, it tends to be robust across different patient hemoglobins and less affected by common variants that can interfere with other methods. Its simplicity and compatibility with automated systems also contribute to it being described as a preferred method for routine HbA1c measurement.