Method of pretreatment of sample for quantitating cholesterol and method for quantitating cholesterol in specific lipoproteins by using the same

Abstract

A method of a pretreatment of a sample for quantitating cholesterol characterized by, before measuring cholesterol contained in specific lipoproteins, treating the sample containing lipoproteins with an enzyme, the substrate of which is free cholesterol, optionally together with a reaction accelerator; a method for quantitating cholesterol in specific lipoproteins by using the above method; and a kit for quantitating cholesterol in specific lipoproteins to be used in the above quantification method. By using this quantification method, cholesterol in a specific fraction can be conveniently, accurately and efficiently quantitated fundamentally without resort to polyanion, etc. Thus, this method is appropriately usable in various automatic analyzers.

1 . A method for quantitating free cholesterol and an esterified cholesterol in a sample which contains various lipoproteins, which comprises causing at least an enzyme, which acts upon free cholesterol as a substrate, cholesterol esterase, and a reaction accelerator, which is selected from flufenamic acid, mefenamic acid, 2,2′,6′,2″-terpyridine, tiglic acid, fusidic acid, betamethasone acetate, monensin and mevinolin, to act upon said free cholesterol. 
     
     
         2 . The method of  claim 1 , further comprising reacting the sample with a cholesterol measuring enzyme reagent to produce a detectable signal and measuring the signal to quantitate the total cholesterol in the sample. 
     
     
         3 . A method for quantitating cholesterol existing in a specific lipoprotein in a sample, which comprises causing cholesterol oxidase, which acts upon free cholesterol as a substrate, to act upon said sample with said lipoprotein contained therein to convert only said free cholesterol under conditions that said lipoproteins remain substantially unchanged; and then measuring said cholesterol, which exists in said specific lipoprotein, by using a substance which acts upon said specific lipoprotein only.