A method for determination of xylose utilizing glucose dehydrogenase

Area of Science:

• Biochemistry
• Clinical Chemistry
• Enzymology

Background:

• Accurate determination of D-xylose is crucial for various clinical diagnostic applications.
• Existing methods for xylose measurement may face interference from glucose.
• Development of selective and reliable D-xylose assays is an ongoing area of clinical chemistry research.

Purpose of the Study:

• To describe a novel method for quantifying D-xylose in biological specimens (serum and urine) using the Ciba-Corning 550 Express analyzer.
• To validate the accuracy, precision, and reliability of the proposed D-xylose determination method.

Main Methods:

• A two-step enzymatic approach involving initial glucose removal using glucose oxidase.
• Subsequent D-xylose determination utilizing the enzymatic action of glucose dehydrogenase (GDH) in the presence of NAD.
• Spectrophotometric measurement of NADH production at 340/380 nm after incubation and filtration.

Main Results:

• The method demonstrated good linearity up to 7.50 mmol/L.
• Day-to-day imprecision (CV%) was low, ranging from 1.8% to 2.7% at different concentrations.
• High recovery rates (96-106%) were observed for both serum and urine samples.
• The assay showed good correlation with established automated methods.

Conclusions:

• The described method provides a reliable and precise means for D-xylose determination in serum and urine.
• The enzymatic approach effectively minimizes interference from glucose, enhancing assay specificity.
• This method is suitable for routine clinical laboratory use on the Ciba-Corning 550 Express platform.