Clinical Chemistry Link to Randox Laboratories Web Site
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 27: 444-450, 1981;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
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 Google Scholar
Google Scholar
Right arrow Articles by Jongen, M. J.
Right arrow Articles by Netelenbos, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jongen, M. J.
Right arrow Articles by Netelenbos, J. C.

Clinical Chemistry, Vol 27, 444-450, Copyright © 1981 by American Association for Clinical Chemistry

Analysis for 1,25-dihydroxyvitamin D in human plasma, after a liquid- chromatographic purification procedure, with a modified competitive protein-binding assay

MJ Jongen, WJ van der Vijgh, HJ Willems and JC Netelenbos

1,25-Dihydroxyvitamin D in plasma is measured by competitive protein- binding assay after isolation from plasma. The present method is improved, as compared with those hitherto described, with regard to receptor preparation, isolation of vitamin D metabolites from plasma, and procedure for the competitive protein binding. Receptor preparation from healthy rather than rachitic chicks, together with a fast isolation procedure, results in a high yield of active receptor protein: 12 animals provide receptor for about 4000 incubations. No loss of binding activity was observed during one year. 1,25- Dihydroxyvitamin D is isolated from plasma by a single extraction and a one-step chromatographic purification. Analytical recovery for the entire procedure averaged 78.1% (SD 4.7%). Other vitamin D metabolites (25-hydroxyvitamin D and 24,25-dihydroxyvitamin D) can also be separated with this procedure. The main features of the modified binding assay are the use of a stabilized cytosol receptor and dextran- coated charcoal instead of polyethylene glycol. The smallest detectable amount in the binding assay is 1-2 pg (2.4-4.8 fmol). Intra- and interassay CVs are 7.0% and 4.8%, respectively. 1,25-Dihydroxyvitamin D concentrations in plasma of 20 healthy subjects averaged 51.7 (SD 10.8) ng/L [124 (SD 26) pmol/L]. Three anephric patients showed values of 3, 6, and 7 ng/L (7, 14, and 17 pmol/L).




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1981 by the American Association for Clinical Chemistry.