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PubMed · 9732985

Luminometric single step urea assay using ATP-hydrolyzing urease.

B Näslund·L Ståhle·A Lundin·B Anderstam·P Arner·J Bergström
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Abstract

An automatic enzyme kinetic luminometric method for determination of small quantities of urea in biological fluids and in microdialysates is presented. The method is based on the ATP-hydrolyzing urease reaction [urea amidohydrolase (ATP-hydrolyzing); EC 3.5.1.45], monitored by a luciferin-luciferase ATP reaction. The assay range is 100 pmol to 50 nmol with a detection limit of 5 micromol/L in the sample, compared with detection limits of 0.1 mmol/L in earlier spectrophotometric methods. To reduce the non-urea-dependent ATPase activity (v(blank)) and to increase the urea-dependent activity, 1,2-propanediol was included. Assay conditions were optimized by multivariate analysis. Recoveries of urea added to blood dialysate and plasma were 96-103%. No analytical interference of common metabolites, drugs, or other additives was observed. The total CVs (6 days and six concentrations, 1.2-21.8 mmol/L) were 3.6-8.5%. The results obtained with the present assay were highly correlated for dialysate (r = 0.979) and for plasma (r = 0.978) with those obtained by a spectrophotometric kit method with slopes of 1.02-1.03 and intercepts of 0.08-0.23 mmol/L.

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Adenosine TriphosphateAdipose TissueAlcoholsAmidohydrolasesFirefly LuciferinHumansKidney DiseasesLuciferasesLuminescent MeasurementsMicrodialysisMultivariate AnalysisRenal DialysisSensitivity and SpecificityUreaComparative StudyJournal ArticleResearch Support, Non-U.S. Gov't

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B Näslund, L Ståhle, A Lundin, B Anderstam, P Arner, J Bergström. 1998. Luminometric single step urea assay using ATP-hydrolyzing urease.. https://pubmed.ncbi.nlm.nih.gov/9732985/

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