Biomaterial Database

Enzymatic assay for methotrexate in serum and cerebrospinal fluid. 1976

L C Falk, and D R Clark, and S M Kalman, and T F Long

We describe an assay for methotrexate in biological fluids. The assay is based on inhibition by methotrexate of dihydrofolate reductase from Lactobacillus casei. The lower limit of sensitivity in serum is 2 X 10(-8) mol (about 10 mug) of methotrexate per liter. Within-run precision is +/- 5% (coefficient of variation) and day-to-day variation is 18%. Advantages of the assay are ease of manipulation, high sensitivity, and specificity.

UI	MeSH Term	Description	Entries
D007780	Lacticaseibacillus casei	A rod-shaped bacterium isolated from milk and cheese, dairy products and dairy environments, sour dough, cow dung, silage, and human mouth, human intestinal contents and stools, and the human vagina. L. casei is CATALASE positive.	Lactobacillus casei
D008727	Methotrexate	An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.	Amethopterin,Methotrexate Hydrate,Methotrexate Sodium,Methotrexate, (D)-Isomer,Methotrexate, (DL)-Isomer,Methotrexate, Dicesium Salt,Methotrexate, Disodium Salt,Methotrexate, Sodium Salt,Mexate,Dicesium Salt Methotrexate,Hydrate, Methotrexate,Sodium, Methotrexate
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013762	Tetrahydrofolate Dehydrogenase	An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.	Dihydrofolate Dehydrogenase,Dihydrofolate Reductase,Folic Acid Reductase,Acid Reductase, Folic,Dehydrogenase, Dihydrofolate,Dehydrogenase, Tetrahydrofolate,Reductase, Dihydrofolate,Reductase, Folic Acid
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor