LDL Cholesterol, Serum/Plasma — Direct Assay, Mass Concentration
A direct blood test that measures the amount of low-density lipoprotein cholesterol in your blood.
["This test measures LDL (“bad”) cholesterol and may be used to assess cardiovascular risk."]
Key facts at a glance
- LOINC
- 18262-6
- Short code
- LDLc SerPl Direct Assay-mCnc
- Synonyms
- LDLc SerPl Direct Assay-mCnc
- Category
- lipid
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- direct-assay
- CPT
- 83721
- SNOMED
- 113079007
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures LDL cholesterol directly in a blood sample. LDL is a particle that carries cholesterol through the bloodstream, and higher amounts are associated with increased risk of heart disease and stroke.
Why might I need this test?
A clinician may order this test as part of a cholesterol screening or follow-up. It can help assess cardiovascular risk, monitor cholesterol-lowering treatment, or clarify the result of a standard cholesterol panel.
How is the test performed?
A blood sample is collected, usually by a venous blood draw, and analyzed in a laboratory using a direct assay. The direct method measures LDL cholesterol rather than calculating it from the other components of a standard lipid panel.
How do I prepare for the test?
Follow any instructions provided by your clinician, especially if you are taking cholesterol-lowering medicines. Fasting may be requested in some situations, but it is not always required for an LDL test.
Reference range
Optimal: <100 mg/dLN/A
Fasting for 12-14 hours preferred. Water is permitted. Avoid alcohol for 24 hours before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A high LDL cholesterol result can indicate increased risk of plaque buildup in the arteries, also called atherosclerosis. This risk is influenced by other factors, including blood pressure, diabetes, smoking, family history, and overall cholesterol levels. Your clinician will interpret the result using your personal risk factors and may recommend lifestyle changes or treatment.
Short name
LDL Cholesterol (Direct)
Frequently asked questions
Is a direct LDL test different from a standard cholesterol panel?
Do I need to fast before this test?
What should I do if my LDL cholesterol is high?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy