Detail Description
"Clinical Significance
Cholesterol, Total (REFL) - Total LDL and HDL cholesterol, in conjunction with a triglyceride determination, provide valuable information for the risk of coronary artery disease. Total serum cholesterol analysis is useful in the diagnosis of hyperlipoproteinemia, atherosclerosis, hepatic and thyroid diseases.
Preferred Specimen(s)
1 mL serum
Alternative Specimen(s)
Sodium heparin (green-top) tube • Lithium heparin (green-top) tube
Minimum Volume
0.5 mL
Transport Container
Serum separator tube (SST)
Transport Temperature
Room temperature
Specimen Stability
Serum
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 90 days
Plasma
Room temperature: 48 hours
Refrigerated: 48 hours
Frozen: 6 months
Reject Criteria
Gross hemolysis • Anticoagulants other than heparin • Moderate to gross icterus
Includes
This is a client specific reflex test. Reflex criteria has been pre-defined by the ordering physician. Additional testing will be performed at an additional charge.
Patient Preparation
If a cholesterol measurement is to be performed along with triglycerides, but not part of a lipid panel, then the patient should be fasting 9-12 hours prior to collection. If the cholesterol is ordered as part of a lipid panel, then a fasting sample is not required.
The assay manufacturer Beckman Coulter advises: "N-Acetyl Cysteine (NAC), when administered in therapeutic concentrations (for the treatment of acetaminophen overdose), has been...determined to interfere with assays for...cholesterol, uric acid" where "NAC interference may lead to falsely low results." According to Beckman Coulter, the NAC interference should be insignificant by 12 hours after completion of the initial loading dose of an IV infusion treatment regimen consisting of an initial loading dose of 150 mg/kg administered over 1 hour, a second dose of 50 mg/kg administered over 4 hours and a third dose of 100 mg/kg administered over 16 hours.
Methodology
Spectrophotometry (SP)
Reference Range(s)
<20 Years <170 mg/dL
≥20 Years <200 mg/dL