title: [Automation of fluorometric enzymatic determination of free and total cholesterol. Application to the determination of the esterification rate].
abstract: A fluorimetric, authomatical method for determination of free and total cholesterol in serum is described. Cholesterol esters are splitted into free cholesterol and fatty acids by cholesterol esterase. In the presence of oxygen free cholesterol will be transformed by cholesterol oxydase in delta 4 cholestenone with formation of hydrogen peroxyde. Hydrogen peroxyde oxidizes in the presence of catalase inethanol to formaldehyde which gives with ammonium ions and acetylacetone 3-5 diacetyl 1-4 dihydrolutidine measured by fluorimetry. Withour cholesterol esterase, the reaction allows a measurement of free cholesterol in plasma. So the ratio of ester to total cholesterol is determined by the two steps. Accuracy and precision are very good. Results are well correlated with those obtained with reference methods.
mesh_terms: D001322:Autoanalysis; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000097:blood*; D002788:Cholesterol Esters / Q000097:blood*; D002845:Chromatography; D004951:Esterification; D005470:Fluorometry / Q000379:methods; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases; D008111:Liver Function Tests; D002787:Sterol Esterase
chemical_list: D002788:Cholesterol Esters; D002784:Cholesterol; D006913:Hydroxysteroid Dehydrogenases; D002787:Sterol Esterase
vernacular_title: Automatisation en fluorimétrie du dosage enzymatique du cholestérol libre et total. Application à la détermination du rapport d'estérification