Clinical Chemistry
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 25: 1370-1372, 1979;
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vinet, B.
Right arrow Articles by Zizian, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vinet, B.
Right arrow Articles by Zizian, L.

Clinical Chemistry, Vol 25, 1370-1372, Copyright © 1979 by American Association for Clinical Chemistry

Enzymic assay for serum theophylline

B Vinet and L Zizian

We describe an original procedure for determination of theophylline in serum. The drug is extracted from 0.4 mL of serum at pH 7.4 with chloroform/isopropanol (20/1 by vol) and back-extracted into sodium hydroxide (1 mmol/L). The inhibition of beef-liver alkaline phosphatases by theophylline in this alkaline phase is measured at 25 degrees C, with p-nitrophenyl phosphate as substrate, in 2-amino-2- methyl-1-propanol buffer, pH 9.4- The reciprocal of enzyme activity and theophylline concentration are linearly related in the range 2 to 60 mg/L. The maximum interference to be expected from 3-methylxanthine would increase apparent theophylline concentration by no more than 1 mg/L. The method is accurate, free of interference by other xanthines and often-coadministered drugs, and results correlate well with those by the immunoenzymic assay. Major advantages are reagent stability, low cost, and simplicity of instrumentation.


The following articles in journals at HighWire Press have cited this article:


Home page
 J Biomol ScreenHome page
P. Schrenkhammer, I. C. Rosnizeck, A. Duerkop, O. S. Wolfbeis, and M. Schaferling
Time-Resolved Fluorescence-Based Assay for the Determination of Alkaline Phosphatase Activity and Application to the Screening of Its Inhibitors
J Biomol Screen, January 1, 2008; 13(1): 9 - 16.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1979 by the American Association for Clinical Chemistry.