Scintillation proximity assay for calcitriol in serum without high pressure liquid chromatography
| Autor: | Karin Dittrich, Susanne Wildermuth, Ingrid Zahn, J.L.H. O'Riordan, Heinrich Schmidt-Gayk |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Adult
Male Calcitriol Clinical Biochemistry Sensitivity and Specificity Biochemistry High-performance liquid chromatography Pregnancy Reference Values medicine Animals Humans Aged Aged 80 and over Detection limit Chromatography Sheep Elution Chemistry Immune Sera Biochemistry (medical) Extraction (chemistry) Radioimmunoassay General Medicine Middle Aged Scintillation proximity assay Scintillation Counting Female Rabbits Quantitative analysis (chemistry) medicine.drug |
| Zdroj: | Clinica Chimica Acta. 220:61-70 |
| ISSN: | 0009-8981 |
| DOI: | 10.1016/0009-8981(93)90006-p |
| Popis: | A rapid isolation step for 1,25-dihydroxyvitamin D3 without high pressure liquid chromatography (HPLC) and a sensitive radioimmunoassay (RIA) have been developed. The time required for extraction and isolation with a combination of Extrelut-1-minicolumns and Sep-Pak silica cartridges from as little as 0.5 ml serum is only 2 h. The assay can be counted after 8 h of incubation. It is performed in the vial that collects the eluate, thus eliminating transfer losses and errors. No separation of bound and free hormone is necessary before beta-counting in the scintillation proximity assay. The detection limit of the assay is 2.7 ng/l. The intra-assay coefficients of variation are 7.3% and 5.2% for samples with calcitriol concentrations of 31 and 148 ng/l, respectively. The inter-assay coefficients of variation are 11.3%, 13.3% and 16.1% for low (16 ng/l), medium (30 ng/l) and high (148 ng/l) control pool samples, respectively. Normal values for calcitriol range from 32 to 80 ng/l. Elderly subjects, patients with reduced kidney function and pregnant women were also evaluated for their calcitriol levels. This assay correlates well with a RIA employing HPLC prepurification and charcoal separation of bound/free calcitriol (r = 0.94). |
| Databáze: | OpenAIRE |
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