Assay principle

Boronate affinity fluorescence quenching for HbA1c

A fluorescent boronic acid conjugate binds the sugar on glycated haemoglobin and goes dark. The size of that drop is the measurement.

Haemoglobin
Glycated haemoglobin, sugar attached
Free conjugate, fluorescing
Bound conjugate, quenched

0.0 / 40 s

Example sample

5.0 % · 31 mmol/mol 7.5 % · 58 mmol/mol 11.0 % · 97 mmol/mol

Schematic, not to scale. Molecule counts are exaggerated so the quench is visible; a real sample holds far more unglycated haemoglobin and a large excess of conjugate. Boronate binds every glycated haemoglobin species, so instruments are calibrated to report the result as HbA1c. Percent values are NGSP units; mmol/mol values are IFCC units, related by NGSP = 0.0915 × IFCC + 2.15.