Low density lipoprotein cholesterol Assay Kit (LDL-C)
For the in vitro quantitative determination of LDL in serum.
Low density lipoproteins (LDL) are synthesized in the liver by the action of various lipolytic enzymes on triglyceride rich very-low-density lipoproteins (VLDLs). Specific LDL receptors exist to facilitate the elimination of LDL from plasma by liver parenchymal cells. It has been shown that most of the cholesterol stored in atherosclerotic plaques originates from LDL. For this reason the LDL-Cholesterol concentration is considered to be the most important clinical predictor, of all single parameters, with respect to coronary atherosclerosis.Accurate measurement of LDLCholesterol is of vital importance in therapies which focus on lipid reduction to prevent atherosclerosis or reduce its progress and to avoid plaque rupture.In this diagnostic test kit an elimination method for the measurement of LDL Cholesterol, without sample pretreatment, is presented which correlates well with precipitation and ultracentrifugation methods.
The assayconsists of 2 distinct reaction steps:
1. Elimination of chylomicron, VLDL-Cholesterol and HDL-Cholesterol by cholesterol esterase, cholesterol oxidase.
Cholesterol esterase Cholesterol ester → Cholesterol + FattyAcid
Cholesterol oxidase Cholesterol + O2 → Cholestenone + H2O2
2. Specific measurement of LDL-Cholesterol after release of LDL-Cholesterol by detergents in Reagent 2.
Cholesterol oxidase
Cholesterol + O2 → Cholestenone + H2O2
Peroxidase
2H2O2 + 4-AA + TODB → Quinone pigment + 4H2
The intensity of the quinoneimine dye produced is directly propoCholesterol oxidase Ortional to the cholesterol concentration when measured at 600 nm.
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