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Serum/plasma concentration of apolipoprotein B (ApoB) by immunoassay

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of apolipoprotein B, a protein found in low-density lipoproteins (LDL), which helps identify cholesterol-related risks.

Quick summary

["ApoB helps assess cholesterol levels and cardiovascular health risk."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
37098-1
Short code
XR C-spine AP+obl+lat W FE
Synonyms
XR C-spine AP+obl+lat W FE
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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 Apolipoprotein B (ApoB)?

Apolipoprotein B (ApoB) is a protein that travels in your blood attached to cholesterol-containing particles, primarily low-density lipoproteins (LDL). LDL is often called 'bad cholesterol' because high levels are linked to increased risk of heart disease and stroke. This test specifically measures the total amount of ApoB in your blood to help evaluate your cholesterol profile.

Why Might You Need This Test?

Your healthcare provider may order an ApoB test if you have high cholesterol, a family history of heart disease, or other risk factors for cardiovascular issues. It can also be used to monitor treatment effectiveness for conditions like hyperlipidemia.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate the plasma or serum, where the ApoB protein is measured using an immunoassay method. Results are typically available within 24 hours.

What Do the Results Mean?

While specific reference ranges vary by lab, higher ApoB levels often correlate with higher LDL cholesterol and increased cardiovascular risk. Your provider will interpret results in the context of your overall health and other test results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: ApoB in Cardiovascular Health

Short name

ApoB Level

Frequently asked questions

How often should I get this test?
The frequency depends on your health status. If you have known cardiovascular risk factors, your provider may recommend testing every 1–3 years or more often if you’re on cholesterol-lowering medication.
What are the normal values for ApoB?
There is no single 'normal' range for ApoB; it varies by lab and individual health. Your results will be compared to your lab’s reference range and discussed with your healthcare provider.
Can lifestyle changes affect ApoB levels?
Yes! Diet, exercise, and quitting smoking can lower ApoB levels. Focus on reducing saturated fats, increasing fiber, and maintaining a healthy weight to support better cholesterol management.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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