Method for measuring glycated albumin

A method of measuring a glycated-albumin (GA) value traceable to a certified GA value, the method comprising:

• A1) determining Regression equation III by which determination comprises the following b), c), and e0) to h):
• b) determining respective GA concentrations[L] (A) of two or more GA certified reference materials having respectively different certified GA values according to the following Equation 1:
• GA concentration[L] (A)=(certified GA value (B) of GA certified reference material)×(albumin concentration (C) of GA certified reference material) (Equation 1)
• c) measuring respective GA-derived absorbances (D) of the two or more GA certified reference materials;
• e0) creating the following linear equation II0 having an intercept of zero:
• D=α0E (Equation II0);
• wherein,
• α0 is an arbitrary positive value and
• E represents a GA concentration[P] (E) proportionate to the GA-derived absorbance (D)),
• f) determining two or more GA concentrations[P] (E) proportionate to the GA-derived absorbances (D) according to the Equation II0;
• g) determining two or more GA values (F) according to the following Equation 2:
• GA value (F)=(GA concentration[P] (E))/(albumin concentration (C)) (Equation 2);
• and
• h) creating the following Regression equation III from the respective certified GA values (B) of the two or more GA certified reference materials and the two or more GA values (F) corresponding thereto:
• B=γF+δ (Regression equation III),
• wherein the GA concentration[L] in each of A1), b), c), and e0) to h) is a concentration of glycated lysine residues (DOF-Lys) and the GA concentration[P] is a concentration of a glycated amino acid or a glycated peptide.

A method of measuring a glycated-albumin (GA) value traceable to the certified GA value, the method comprising:

• A3) determining Regression equation V by which determination comprises the following b) to e0) and j) to o):
• b) determining respective GA concentrations[L] (A) of two or more GA certified reference materials having respectively different certified GA values according to the following Equation 1:
• GA concentration[L] (A)=(certified GA value (B) of GA certified reference material)×(albumin concentration (C) of GA certified reference material) (Equation 1);
• c) measuring respective GA-derived absorbances (D) of the two or more GA certified reference materials;
• d) creating, from the two or more GA-derived absorbances (D) and the two or more GA concentrations[L] (A), the following Regression equation I:
• D=αA+β (Regression equation I);
• e0) creating the following Linear equation II0 having an intercept of zero:
• D=α0E (Equation II0)
• (wherein,
• α0 is an arbitrary positive value and
• E represents a GA concentration[P] (E) proportionate to the GA-derived absorbance (D)),
• j) measuring respective GA-derived absorbances (S) of two or more sample materials and determining GA concentrations[L] J (T) corresponding thereto according to the Regression equation I;
• k) measuring respective albumin-derived absorbances (U) of the two or more sample materials and determining albumin concentrations (V):
• l) determining, from the GA concentrations[L] (T), respective GA values1 (W) of the two or more sample materials according to the following Equation 8:
• GA value1 (W)=(GA concentration[L] (T))/(albumin concentration (V)) (Equation 8);
• m) determining, from the respective GA-derived absorbances (S) of the two or more sample materials, GA concentrations[P] (X) corresponding thereto according to the Equation II0;
• n) determining, from the GA concentrations[P] (X), respective GA values2 (Y) of the two or more sample materials according to the following Equation 9:
• GA value2 (Y)=(GA concentration[P] (X))/(albumin concentration (V)) (Equation 9);
• and
• o) creating, from the GA values1 (W) of the two or more sample materials and the two or more GA values2 (Y) corresponding thereto, the following Regression equation V:
• W=πY+φ (Regression equation V),
• wherein the GA concentration[L] in each of A3), b) to e0) and i) to g) is a concentration of glycated lysine residues (DOF-Lys) and the GA concentration[P] is a concentration of a glycated amino acid or a glycated peptide.