We evaluated the direct fluorometric assay for determining retinol in bovine serum. The concentration of retinol in bovine serum determined by direct fluorometric assay was highly correlated with those by high performance liquid chromatography (HPLC) method (r = 0.955, n = 184), or the retinol binding protein by single radial immunodiffusion assay (r = 0.851, n = 88). Inter-assay coefficient of variation from ten measures of retinol in bovine serum was 4.9%, suggesting that reproductivity of direct fluorometric assay was acceptable for clinical use. There was no significant difference between the HPLC methods and direct fluorometric assay in the presence of hemoglobin up to 0.8 mg/ml, or β-carotene 400μg/ml. The direct fluorometric assay is a simple and inexpensive method, and is considered to be useful for routine retinol assay, in particular, where mass surveillance is required.
(Metabolic Disease Section, Department of Production Diseases TEL +81-29-838-7795)
