MEASURING METHOD OF METHOTREXATE CONCENTRATION IN BODY FLUIDS AND COMBINATION OF MEASURING REAGENT

摘要

PURPOSE:To enable to measure the methotrexate concentration on body fluids with the pH buffer solution consisting of specific compounds and the reagent consisting of NADPH solution, DHF solution, enzyme solution and methotrexert standard solution, correctly and in a short time. CONSTITUTION:The reagent kit for the measurement of methotrexate in body fluids is constituted by the combination of (A) the buffer solution of pH 7.5 consisting of 0.1M tris(hydroxymethyl)aminoethane, 0.01M2-mercaptoethanol and KCl 11.2g, (B) NADPH of 0.5-1mM, (C), DHF of 0.5-1mM, (D) engyme having the relative activity 50mu mol/mg/minute or more, and (E) methotrexate standard solution. The measuring time by this reagent is as short as about 10 minutes and the methotrexate in blood and urine can accurately be measured in a short time. Further, without requiring special equipment and location, the measurement can be made by using the spectrophotometer in hospitals and laboratories.