title: A simplified, colorimetric micromethod for xylose in serum or urine, with phloroglucinol.
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: D002241:Carbohydrates / Q000652:urine; D003124:Colorimetry / Q000379:methods; D006801:Humans; D008832:Microchemistry; D010696:Phloroglucinol; D014994:Xylose / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D002241:Carbohydrates; D014994:Xylose; D010696:Phloroglucinol