|
|
||||||||
Clinical Chemistry, Vol 26, 335-338, Copyright © 1980 by American Association for Clinical Chemistry
LF Brown, GF Johnson, DL Witte and RD Feld
We adapted an inhibition assay for methotrexate, involving dihydrofolate reductase from bovine liver, for use with a discrete analyzer (the ABA-100). The analyzer was used both for dilution and a 5- min pre-incubation of the sample with NADPH--enzyme reagent, and for the assay itself. The standard curve was linear between 10 and 120 microgram/L. Without pre-incubation the standard curve was nonlinear. The presence of albumin in the NADPH--enzyme reagent enhanced both enzyme activity and stability. Within-run precision (CV) was 2.0% (n = 24), run-to-run precision 7.1% (n = 49). Results obtained on patients' samples (29 sera, 15 urines, 18 cerebrospinal fluids) by the present method and a radioimmunoassay method did not differ statistically (p greater than 0.05) when the paired data were analyzed by use of the sign test and Wilcoxon's ranked sign test.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |