Method for measuring cholesterol in low-density lipoprotein, measurement reagent, and measurement kit

A method for measuring cholesterol in total low-density lipoprotein in a sample, the method comprising:

• mixing the sample and an aqueous solvent which comprises:
• (i) a combination of cholesterol ester hydrolase and cholesterol oxidase or (ii) a combination of cholesterol ester hydrolase, an oxidized coenzyme and cholesterol dehydrogenase,
• one or more surfactants selected from the group consisting of a polyoxyethylene alkyl ether and a polyoxyethylene polyoxypropylene alkyl ether,
• a polyoxyethylene polyoxypropylene copolymer and
• a polyoxypropylene derivative not comprising any polyoxyethylene in a molecule, to react cholesterol in low-density lipoprotein in the sample with (i) the combination of cholesterol ester hydrolase and cholesterol oxidase or (ii) the combination of cholesterol ester hydrolase, an oxidized coenzyme and cholesterol dehydrogenase;
• and
• measuring a substance formed or consumed in the reaction,
• with the proviso that the aqueous solvent does not comprise any surfactant having an alkylphenol structure.

A method for measuring cholesterol in low-density lipoprotein in a sample, the method comprising:

• mixing the sample and an aqueous solvent which comprises:
• (i) a combination of cholesterol ester hydrolase and cholesterol oxidase or (ii) a combination of cholesterol ester hydrolase, an oxidized coenzyme and cholesterol dehydrogenase,
• one or more surfactants selected from the group consisting of a polyoxyethylene alkyl ether and a polyoxyethylene polyoxypropylene alkyl ether,
• a polyoxyethylene polyoxypropylene copolymer and
• a polyoxypropylene derivative not comprising any polyoxyethylene in a molecule, to react cholesterol in low-density lipoprotein in the sample with (i) the combination of cholesterol ester hydrolase and cholesterol oxidase or (ii) the combination of cholesterol ester hydrolase, an oxidized coenzyme and cholesterol dehydrogenase;
• and
• measuring a substance formed or consumed in the reaction,
• with the proviso that the aqueous solvent does not comprise any surfactant having an alkylphenol structure,
• wherein the method excludes any removal of cholesterol in lipoprotein other than the low-density lipoprotein in a sample before measurement of the low-density lipoprotein-cholesterol.