I. Chemical methods
|
A. Oxidation-reduction reaction
|
|
1. Alkaline copper reduction
|
Folin-Wu method
|
|
Blue end-product
|
Benedict's method
|
- Modification of Folin–Wu method for qualitative urine glucose.
|
Nelson–Somogyi method
|
|
Blue end-product.
|
Neocuproine method
|
*
|
Yellow-orange color neocuproine
|
Shaeffer–Hartmann–Somogyi
|
- Uses the principle of iodine reaction with cuprous byproduct.
- Excess I2 is then titrated with thiosulfate.
|
2. Alkaline Ferricyanide reduction
|
Hagedorn–Jensen
|
|
Colorless end product; other reducing substances interfere with reaction.
|
B. Condensation
|
Ortho-toluidine method
|
|
Anthrone (phenols) method
|
- Forms hydroxymethyl furfural in hot acetic acid
|
II. Enzymatic methods
|
A. Glucose oxidase
|
|
Saifer–Gerstenfeld method
|
|
Inhibited by reducing substances like BUA, bilirubin, glutathione, ascorbic acid.
|
Trinder method
|
|
Kodak Ektachem
|
- A dry chemistry method.
- Uses spectrophotometry to measure the intensity of color through a lower transparent film.
|
Glucometer
|
- Home monitoring blood glucose assay method.
- Uses a strip impregnated with a glucose oxidase reagent.
|
B. Hexokinase
|
|
- NADP as cofactor.
- NADPH (reduced product) is measured in 340 nm.
- More specific than glucose oxidase method due to G-6PO4, which inhibits interfering substances except when sample is hemolyzed.
|