Sucrose and D-glucose are two of the most commonly occurring sugars in plant and food products and have serious impacts on human nutrition. D-Glucose can be conveniently measured in body fluids using commercially available kits based on the glucose oxidase/peroxidase or on the hexokinase/G6PDH enzymatic procedures. However, D-glucose in plant extracts usually occurs together with maltose, maltosaccharides, starch, sucrose and/or β-linked Dglucooligosaccharides. Consequently, more stringent requirements are placed on the purity of the assay reagents. The reagents must be essentially devoid of starch degrading enzymes, sucrose degrading enzymes and β-glucosidase, as these can lead to either an overestimation or an underestimation of free D-glucose present in the extract or derived by specific enzymic degradation of glucose containing oligosaccharides or polysaccharides (e.g. barley β-glucan). This Sucrose/D-Glucose Test Kit employs high purity glucose oxidase, peroxidase and β-fructosidase (invertase) and can be used with confidence for the specific measurement of Dglucose and sucrose in plant and food extracts.