A simplified, colorimetric micromethod for xylose in serum or urine, with phloroglucinol

Clin Chem. 1979 Aug;25(8):1440-3.

Abstract

We have developed a simplified xylose assay procedure that requires only 10 min and requires 50 microL of serum or 5 microL of urine. The reaction with phloroglucinol is more sensitive than the classic p-bromaniline color reaction, and requires only 4 min of heating for color development. A single reagent is mixed with the specimen directly, without prior protein precipitation. Analytical recovery of xylose added to serum was quantitative; precision studies resulted in a between-day coefficient of variation of 5.2%. Glucose, which has significant potential for interference in most other xylose procedures, reacts under the test conditions only to the extent of 70 mumol of apparent xylose per liter for a 5.5 mmol/L solution of glucose. The new procedure has been valuable in the assessment of malabsorption, especially in children and infants, where serum xylose is the preferred measurement.

MeSH terms

  • Carbohydrates / urine
  • Colorimetry / methods
  • Humans
  • Microchemistry
  • Phloroglucinol*
  • Xylose / analysis*
  • Xylose / blood
  • Xylose / urine

Substances

  • Carbohydrates
  • Xylose
  • Phloroglucinol