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Apolipoprotein A-I, Plasma — Mass Concentration

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

This blood test measures the amount of apolipoprotein A-I, a major protein component of high-density lipoprotein (HDL), in plasma.

Quick summary

["Apolipoprotein A-I helps assess cholesterol transport and may be interpreted alongside the rest of your lipid profile."]

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

Key facts at a glance

LOINC
16342-8
Short code
A-AIB Plas-mCnc
Synonyms
A-AIB Plas-mCnc
Category
liver
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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?

Apolipoprotein A-I, also called Apo A-I, is a protein found in high-density lipoprotein (HDL), commonly known as “good” cholesterol. This test measures the concentration of Apo A-I in a plasma sample.

Why might I need this test?

This test may be ordered to help evaluate cholesterol levels and cardiovascular risk, particularly when results from a standard lipid panel need additional context. It is usually interpreted together with total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides.

How is the test performed?

A blood sample is collected and separated into plasma. The laboratory then measures the amount of Apo A-I using an analytical method such as an immunoassay or another validated protein-measurement technique.

How do I prepare for the test?

Fasting is not always required, but you may be asked to fast if this test is being performed with other lipid tests. Follow the laboratory’s instructions and tell your clinician about any cholesterol-lowering medicines or supplements you use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Apolipoprotein A-I (Apo A-I)

Frequently asked questions

Is Apo A-I the same as HDL cholesterol?
No. HDL cholesterol measures the amount of cholesterol carried in HDL, while Apo A-I measures one of the main proteins in those particles. The measurements are related and are often evaluated together.
Does this test diagnose heart disease?
No. It provides information about one aspect of cholesterol transport and cardiovascular risk, but it does not diagnose heart disease by itself.
Do I need to fast before the test?
Fasting requirements depend on the laboratory and the other tests ordered with it. Ask your healthcare provider whether you should fast before your blood draw.
  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