Direct HbA1c │OEM Liquid Reagent for Clinical Chemistry (Enzymatic)│Biotechnology Operating Department│TOYOBO| Biotechnology Operating Department │TOYOBO

NGSP-certified method
Direct enzymatic assay, no latex particles
Uses a single channel on the analyzer
Good in-use stability, stable for 4 weeks on board
Ready-to-use liquid reagent


Hemoglobin A1c (HbA1c) produces glycosylated dipeptide and H2O2 when exposed to protease.
Hemoglobin (Hb) is simultaneously denatured and autoxidized by an oxidant.
Hb is ultimately converted to methemoglobin.
H2O2 except the amount which is essential to color for assaying HbA1c percentage, is used in the methemoglobinization reaction.
Thus, regardless of the difference in the amount of hemoglobin between specimens, the HbA1c percentage can be assayed directly within the measurement range.


Single step: Direct measurement of HbA1c percentage

Single Step: Direct measurement on % of HbA1c

Assay specifications

Method Enzymatic assay
Specimen sample EDTA or NaF whole blood
Number of channels 1
Calibration 2-point calibration
Measurement range 4%–16% (as NGSP value)
Correlation HPLC method: r = 0.9832
Reproducibility Within-run: CV <5%
In-use stability 4 weeks at 2°C–8°C

Correlation with HPLC method using clinical specimens (n = 50)

Correlation with HPLC method using clinical specimens (n = 50)

No interference from the following.

Ascorbic acid: <20 mg/dL, bilirubin (free or conjugated, <12 mg/dL)
Chyle: <3,000 formazin turbidity units
Glucose: <1,000 mg/dL
Hemoglobin variant (HbF): <9.5%
Hemoglobin variant (HbS): <27.6%
Modified Hb (acetyl Hb, carbamoyl Hb, and acetaldehyde Hb): <50 mg/dL each

Assay procedure (e.g., Hitachi 917 analyzer)

Assay procedure

A1 is the difference in absorbance between 800 and 660 nm after 5 min.
A2 is the difference in absorbance between 800 and 660 nm after 10 min.
HbA1c percentage is calculated as the difference between A1 and A2

Reagent composition

Lysis buffer
Reagent 1 solution (R1)* Each reagent is stable for 12
Reagent 2 solution (R2)months when stored at 2°C–8°C


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