HDL Cholesterol

367

Lipids

HDL cholesterol

Serum or heparinised plasma

R1: 2 x 31.5 mL;
R2: 2 x 10.5 mL,
Ready for use

Instructions for Use  |  Safety Data Sheet

For professional use only.

Cholesterol is in part synthesised in the organism and is in part introduced through the diet. It is an essential component of the cell membrane and lipoproteins and is a precursor for the synthesis of steroid hormones and biliary acids. About 25% of the total cholesterol present in the serum is transported by lipoproteins in the high-density fraction (HDL, High Density Lipoproteins). About 50% of the HDL mass is composed of proteins, 30% of phospholipids and the remaining 20% of cholesterol. The liver and intestine are both involved in the production of HDL which seems to play an important role in the efflux of cholesterol from peripheral tissues, reducing the amount of cholesterol stored therein. HDL also have a role in the mechanism of bringing back the cholesterol from the peripheral tissue to the liver to be eliminated and transformed into biliary acids, this metabolic mechanism being know by the term “inverse transport of cholesterol”. As there is an inverse correlation between the HDL plasma concentration and the incidence of coronary heart disease, an accurate determination of the HDL cholesterol is essential to establish eventual risk factors related to coronary heart disease. The various techniques available for determination of HDL cholesterol levels include ultracentrifugation, electrophoresis, HPLC (high performance liquid chromatography) and methods based on precipitation. For all these reasons, from the clinical aspect the need was felt to develop a practical, reliable method which does not require preliminary treatments.

The HDL-L reagent is produced using a combination of detergents and phosphorus compounds which specifically bind LDL, VLDL and CM (chilomicrons) but not HDL. This combination impedes LDL, VLDL and CM from reacting with CO (cholesterol oxidase) and CE (cholesterol esterase), while HDL-cholesterol is able to react with both enzymes.
HDL (cholesterol esters) + H2O --(CE)--> Cholesterol + Fatty Acid
free Cholesterol + O2 --(CO)--> Delta4-cholestenon + H2O2
2H2O2 + 4-AA + HDAOS --(POD)--> 4H2O + Quinone dye
The compound (Quinone dye) which forms is read at λ 578 nm, develops a colour, the intensity of which is proportional to the HDL concentration in the test sample.

Store at 2 - 8°C avoiding direct light. The reagent thus stored is stable until the expiry date shown on the label. Slight variation in component composition may occur from batch to batch without affecting test results. Once opened, they are stable for 30 days if immediately closed and protected from contamination, evaporation, direct light and stored at the correct temperature.

HDL/LDL cholesterol calibrator (R0300000009)
Normal control serum (R0400000006)
Pathological control serum (R0400000106)
Control Serum for Cholesterol HDL-LDL (R0400000300)