Method and kit for quantitative determination for small, dense particle low density lipoproteins

1. A method for quantitatively determining small, dense LDL cholesterol, comprising:

adding enzymes for cholesterol measurement to a test sample in the presence of a polyoxyethylene-polyoxypropylene copolymer represented by formula (II):

RO—(C 3 H 6 O) d —(C 2 H 4 O) e —(C 3 H 6 O) f —H  (II),

wherein a is an integer between 1 and 200, b is an integer between 1 and 200, c is an integer between 1 and 200, d is an integer between 1 and 60, e is an integer between 20 and 100, and f is an integer between 1 and 60,

wherein R denotes a hydrogen atom or linear or branched alkyl having a carbon number ranging from C1 to C30;

(ii) causing the polyoxyethylene-polyoxypropylene copolymer to selectively act on small, dense LDLs among lipoproteins, and then

(iii) measuring the amount of cholesterol generated.

2. The method according to claim 1 , comprising further adding a nonionic and/or anionic surfactant.

3. The method according to claim 1 , wherein the enzymes for cholesterol measurement comprise cholesterol esterase as well as cholesterol oxidase or cholesterol dehydrogenase.

4. The method according to claim 1 , further comprising adding phospholipase and/or lipoprotein lipase.

5. The method according to claim 1 , further comprising, before step (ii), eliminating or aggregating cholesterols other than small, dense LDLs.