Summary: Direct Enzymatic HbA1c test is an enzymatic assay in which lysed whole blood samples are subjected to extensive protease digestion with Bacillus sp protease. This process releases amino acids including glycated valines from the hemoglobin beta chains. Glycated valines then serve as substrates for specific recombinant fructosyl valine oxidase (FVO) enzyme, produced in E. coli. The recombinant FVO specifically cleaves N-terminal valines and produces hydrogen peroxide. This, in turn, is measured using a horseradish per-oxidase (POD) catalyzed reaction and a suitable chromagen. The HbA1c concentration is expressed directly as %HbA1c by use of a suit-able calibration curve in which the calibrators have values for each level in %HbA1c.