The present disclosure relates to systems and methods for measuring glycated A1c hemoglobin. A glycated hemoglobin level measuring system includes a sample testing apparatus having a microchannel that compresses a blood sample traveling through, a first pair of electrodes coupled to the microchannel, and a second pair of electrodes coupled to the microchannel. The glycated hemoglobin level measuring system further includes an analysis apparatus having sensors coupled to the first and second pairs of electrodes and configured to calculate a travel time taken by a red blood cell to pass through the first and second pairs of electrodes. The glycated hemoglobin level measuring system can use the travel time to measure a rigidity of the red blood cells and the corresponding glycated hemoglobin level.

Provided is a method for estimating a hemoglobin A1c level including acquiring in advance a correlation between a hemoglobin A1c level which is based on the ratio of the peak value of a hemoglobin A1c peak to the total of the peak values related to hemoglobin A and a glycated mutant hemoglobin level which is based on the ratio of the peak value of a glycated mutant hemoglobin peak to the total of the peak values containing mutant hemoglobin and the peak value of the glycated mutant hemoglobin peak containing glycated mutant hemoglobin formed by glycating the mutant hemoglobin, from a chromatogram of a blood specimen that contains the hemoglobin A and the mutant hemoglobin, deriving a glycated mutant hemoglobin level from a chromatogram of a blood specimen, and estimating a hemoglobin A1c level based on the derived glycated mutant hemoglobin level and the correlation.

The present disclosure relates to systems and methods for measuring glycated A1c hemoglobin. A glycated hemoglobin level measuring system includes a sample testing apparatus having a microchannel that compresses a blood sample traveling through, a first pair of electrodes coupled to the microchannel, and a second pair of electrodes coupled to the microchannel. The glycated hemoglobin level measuring system further includes an analysis apparatus having sensors coupled to the first and second pairs of electrodes and configured to calculate a travel time taken by a red blood cell to pass through the first and second pairs of electrodes. The glycated hemoglobin level measuring system can use the travel time to measure a rigidity of the red blood cells and the corresponding glycated hemoglobin level.

Methods, devices, and reagents are described for performing ratiometric assays for hemoglobin A1c. The methods involve a direct ratio determination between Hb A1c and normalized total hemoglobin utilizing a saturating amount of hemoglobin so that Hb A1c binds proportionately to a substrate. In some applications, the assay utilizes a proximity label system for signal generation and/or labeled magnetic beads. The methods can be configured as homogeneous or heterogeneous assays.

Kits, microfluidics devices, and assays for use in methods of spectroscopically determining a ratio of glycated hemoglobin to total hemoglobin in a whole blood sample are disclosed.

Provided is a method for measuring a glycoprotein using an enzymatic method, and the method includes simplified steps.

Methods, devices, and reagents are described for performing ratiometric assays for hemoglobin A1c. The methods involve a direct ratio determination between Hb A1c and normalized total hemoglobin utilizing a saturating amount of hemoglobin so that Hb A1c binds proportionately to a substrate. In some applications, the assay utilizes LOCI or other proximity label for signal generation and/or labeled magnetic beads. The methods can be configured as homogeneous or heterogeneous assays.

This invention provides an HbA1c dehydrogenase that is capable of directly acting on hemoglobin A1c and is less likely to be influenced by oxygen concentration and a method for measurement and a kit of assay reagents using such HbA1c dehydrogenase. The HbA1c dehydrogenase having dehydrogenase activity and capable of directly acting on HbA1c is obtained by substitution of one or more amino acid residues at positions corresponding to positions 280, 269, 54, 241, and 267 of the amadoriase that is capable of directly acting on hemoglobin A1c and is derived from, for example, the genus Coniochaeta. This invention also provides a method for measurement of HbA1c, a kit of assay reagents, and a sensor using such HbA1c dehydrogenase. Such HbA1c dehydrogenase is capable of directly acting on hemoglobin A1c and has lowered oxidase activity and/or enhanced dehydrogenase activity. This not only eliminates the need for treatment of hemoglobin A1c with a protease but also enables the use of an electron mediator in the measurement of HbA1c, thereby reducing effects due to oxygen concentration, and enables HbA1c measured with high sensitivity.

The objective is to obtain results of measurement, by cation exchange chromatography, of sA1c reflecting symptoms of a subject who provided a blood sample containing abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C by eliminating influences by such abnormal hemoglobin.

The above objective is achieved by a method for measuring the proportion of sA1c (%), which comprises, when a peak derived from abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C is identified, calculation of the peak area, and measurement of the proportion of sA1c (%) corrected by using the calculation results.

Methods, devices, and systems may use a kinetic model to determine physiological parameters related to the kinetics of red blood cell glycation, elimination, and generation. Such physiological parameters can be used, for example, to determine a more reliable calculated HbA1c. In another example, a method may comprise: receiving a plurality of glucose levels over a time period; receiving a glycated hemoglobin (HbA1c) level corresponding to an end of the time period; determining at least one physiological parameter selected from the group consisting of: a red blood cell glycation rate constant (k.sub.gly), a red blood cell generation rate constant (k.sub.gen), a red blood cell elimination constant (k.sub.age), and an apparent glycation constant (K), based on (1) the plurality of glucose levels and (2) the HbA1c level; and adjusting a glucose level target based on the at least one physiological parameter.