Low-Density Lipoprotein Cholesterol (LDL-C) Assay Kit (Two-Reagent Direct Method, Colorimetric Method)

Cat. No.: L1527117

GRADE & PURITY BioReagent

Overview

This kit employs a selective surfactant method for the direct determination of low-density lipoprotein cholesterol (LDL-C). In the assay system composed of cholesterol esterase (CHER) and cholesterol oxidase (CHOD), a specific surfactant is added to selectively solubilize LDL-C and release cholesterol, which then participates in the subsequent enzymatic reactions. Meanwhile, other lipoproteins such as HDL, VLDL, and chylomicrons are inhibited by the combined action of the surfactant and sugar compounds, and thus do not participate in the reactions but remain as intact lipoproteins in the reaction solution, enabling the direct determination of LDL-C. The specific principle of the assay is as follows: The cholesterol esters released from LDL-C are hydrolyzed by cholesterol esterase to generate free cholesterol (FC). FC is then oxidized by cholesterol oxidase to produce 4-cholestenone and hydrogen peroxide (H₂O₂). In the presence of peroxidase (POD), H₂O₂ undergoes an oxidative coupling reaction with 4-aminoantipyrine (4-AAP) and a phenolic chromogenic reagent to form a red quinone imine compound, which exhibits a characteristic absorbance peak at 546 nm. By measuring the increase in absorbance at this wavelength and referencing a standard curve, the LDL-C content in the sample can be precisely calculated.

Storage and Shipping

Storage

Store at 2-8°C

Shipped In

Wet ice