Laboratory Test DirectoryShare
Measurements of cholesterol are used primarily in the diagnosis and treatment of disorders involving excess cholesterol in the blood, and lipid and lipoprotein metabolism disorders.
Total serum cholesterol analysis has proven useful in the diagnosis of hyperlipoproteinemia, atherosclerosis, hepatic and thyroid diseases. Total and HDL cholesterols, in conjunction with a triglyceride determination, provide valuable information for the prediction of coronary heart disease.
Cholesterol esters in serum are hydrolyzed by cholesterol esterase (CHE). The free cholesterol produced is oxidized by cholesterol oxidase (CHO) to cholest-4-en-3-one with the simultaneous production of hydrogen peroxide (H202), which oxidatively couples with 4-aminoantipyrine and phenol in the presence of peroxidase to yield a chromophore.
The red quinoneimine dye formed can be measured spectrophotometrically at 540/600 nm as an increase in absorbance.
Collect: Serum Separator Tube (SST) - 0.5 ml
Specimen preparation: Serum free from hemolysis is the recommended specimens. Allow blood samples to clot (15 mins). Separate the serum from the cells by centrifuging for 10 minutes. Store serum at 2-8°C until analysis.
Stability: Total cholesterol in serum is stable for 7 days when stored at 2-8°C, 3 months when stored <-20°C, and for over one year stored at <-70°C.
At Accu Reference: Refrigerated -7 days: Frozen- 1 month
NOTE: * This test is approved for all states. *
Accu Reference Medical Laboratory
Total Cholesterol Risk Classification
< 200 mg/dL Desirable
200 - 239 mg/dL Borderline High
> 240 mg/dL High
The assay Reportable Range is from 25.0 to 700.0 mg/dL. Samples exceeding the upper limit of linearity are diluted and repeated.