Reducing sugar is widely found in animals, plants, microorganisms and cultured cells. Reducing sugars in
plants mainly include glucose, fructose and maltose, which are the most common monosaccharides and
disaccharides. Glucose and fructose are not only the main substrates of respiration, but also the substrates
for further synthesis of sucrose, starch and cellulose.
Heating can promote the formation of brownish red amino compound from 3,5-Dinitrosalicylic acid
solution and reducing sugar in alkaline solution. This brownish red amino compound has a characteristic
absorption peak at 540 nm. Within a certain concentration range, the content of reducing sugar has a linear
relationship with the absorbance at 540 nm. According to the standard curve, the amount of reducing sugar
in the sample can be calculated.
Reagents and Equipment Required but Not Provided.
Spectrophotometer/microplate reader, water-bath, table centrifuge, transferpettor, micro glass cuvette/96
well flat-bottom plate, mortar and distilled water.
