Abstract: Provided are a method which enables more accurate quantification of lipoprotein cholesterol in a test sample, and a quantification reagent and a quantification kit used for this method. The present invention provides a quantification method for lipoprotein cholesterol in a test sample containing a lipoprotein optionally using a quantification reagent, the method including adding a phospholipid to the test sample or the quantification reagent. The present invention also provides a quantification reagent for cholesterol in a lipoprotein used in the method of the present invention, the quantification reagent containing a phospholipid. The present invention also provides a quantification kit for lipoprotein cholesterol used in the method of the present invention, the quantification kit containing a phospholipid.

Abstract: Disclosed are a method and reagent of quantifying cholesterol in triglyceride-rich lipoprotein (TRL-C) in a test sample in a more specific manner without requiring laborious operations. The method of quantifying cholesterol in triglyceride-rich lipoprotein (TRL-C) includes the steps of: (1) selectively eliminating cholesterol in lipoproteins other than triglyceride-rich lipoprotein (TRL) by allowing a cholesterol esterase having a molecular weight of more than 50 kDa and a surfactant(s) to act; and (2) quantifying the remaining TRL-C.

Abstract: Disclosed is a method for reducing measurement errors due to inhibition of catalase by azide in a method for quantification of a component to be measured, in which hydrogen peroxide derived from a component other than the component to be measured is decomposed by a catalase. The method for reducing measurement errors due to inhibition of catalase by azide employs a catalase which has a subunit having a molecular mass of 75 kDa or higher and is derived from a microorganism, when hydrogen peroxide derived from a component other than the component to be measured is decomposed by the catalase followed by quantification of hydrogen peroxide derived from the component to be measured to quantify the component to be measured.

Abstract: Disclosed is the provision of a method for quantifying HDL3 in a test sample without requiring a laborious operation. The method for quantifying cholesterol in high-density lipoprotein 3 comprises allowing a surfactant(s) which specifically react(s) with a high-density lipoprotein 3 to react with a test sample and quantifying cholesterol, and the surfactant(s) is(are) at least one selected from the group consisting of polyoxyethylene polycyclic phenyl ether and polyoxyethylene styrenated phenyl ether.

Abstract: Disclosed is the provision of a method for quantifying HDL3 in a test sample without requiring a laborious operation. The method for quantifying cholesterol in high-density lipoprotein 3 comprises allowing a surfactant(s) which specifically react(s) with a high-density lipoprotein 3 to react with a test sample and quantifying cholesterol, and the surfactant(s) is(are) at least one selected from the group consisting of polyoxyethylene polycyclic phenyl ether and polyoxyethylene styrenated phenyl ether.

Abstract: A method for quantifying remnant-like lipoprotein cholesterol in a sample simply and accurately without requiring separation operations, and a kit therefor are disclosed. A method for quantifying cholesterol in a remnant-like lipoprotein in a sample containing different lipoproteins including the remnant-like lipoprotein comprises a step (1) of erasing cholesterol in lipoproteins other than the remnant-like lipoprotein; and a step (2) of quantifying cholesterol in the remaining remnant-like lipoprotein. The step (1) is carried out under an action of a cholesterol esterase having a molecular weight of more than 40 kDa and not having a subunit having a molecular weight of not more than 40 kDa; and the step (2) is carried out under an action of a cholesterol esterase having a molecular weight of not more than 40 kDa or a cholesterol esterase having a subunit having a molecular weight of not more than 40 kDa.

Abstract: A method for quantifying remnant-like lipoprotein cholesterol in a sample simply and accurately without requiring separation operations, and a kit therefor are disclosed. A method for quantifying cholesterol in a remnant-like lipoprotein in a sample containing different lipoproteins including the remnant-like lipoprotein comprises a step (1) of erasing cholesterol in lipoproteins other than the remnant-like lipoprotein; and a step (2) of quantifying cholesterol in the remaining remnant-like lipoprotein. The step (1) is carried out under an action of a cholesterol esterase having a molecular weight of more than 40 kDa and not having a subunit having a molecular weight of not more than 40 kDa; and the step (2) is carried out under an action of a cholesterol esterase having a molecular weight of not more than 40 kDa or a cholesterol esterase having a subunit having a molecular weight of not more than 40 kDa.

Abstract: Disclosed is a method for reducing measurement errors due to inhibition of catalase by azide in a method for quantification of a component to be measured, in which hydrogen peroxide derived from a component other than the component to be measured is decomposed by a catalase. The method for reducing measurement errors due to inhibition of catalase by azide employs a catalase which has a subunit having a molecular mass of 75 kDa or higher and is derived from a microorganism, when hydrogen peroxide derived from a component other than the component to be measured is decomposed by the catalase followed by quantification of hydrogen peroxide derived from the component to be measured to quantify the component to be measured.

Abstract: This invention provides a method for differentially and simultaneously quantifying two target analytes via a single assay operation with the use of a single type of reagent in each of the two steps, i.e., the first step and the second step. In this method, the reaction product associated with the first target analyte is detected at an early stage of the second step and the reaction product associated with the second target analyte is then detected.