This assay is used for the quantitative determination of hemoglobin A1c (HbA1c) in whole blood, reported as both mmol/mol (IFCC) and % (DCCT/NGSP). HbA1c reflects long-term blood glucose control over the past 2 to 3 months and is essential for monitoring diabetes and identifying individuals at risk. It forms through a non-enzymatic reaction between glucose and the N-terminal of the β-chain of hemoglobin A, initially creating a labile form, which then stabilizes as HbA1c. The proportion of HbA1c increases with higher average blood glucose, and since red blood cells live for 100–120 days, HbA1c levels serve as a reliable indicator of long-term glycemic status. Common testing methods include ELISA, chemiluminescence, and immunofluorescence.
