A competitive protein-binding assay for 25-hydroxyvitamin D.
1. We describe a modified competive protein-binding assay for 25-hydroxyvitamin D, which does not require the prior separation of vitamin D from 25-hydroxyvitamin D. 2. Bovine albumin was used in the buffer, at a concentration of 1mg/ml, as a protein stabilizer and lipid solubilizer. Bovine albumin from different manufactures produced very different non-specific binding of 25-(3H)hydroxycholecalciferol (ranging from 3.3 per cent to 58.9 per cent). 3. The mean concentration of 25-hydroxyvitamin D in sera from normal children in Johannesburg was 76.75 +/- 24.75 mumol/ml (30.7 +/- 9.9 ng/ml).
D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D002648:Child; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood*; D011485:Protein Binding; D051381:Rats; D012710:Serum Albumin, Bovine
D006887:Hydroxycholecalciferols; D012710:Serum Albumin, Bovine