Alpha-2-Macroglobulin, Serum/Plasma — Mass Fraction
Measures the amount of alpha-2-macroglobulin, a large blood protein, in serum or plasma to help evaluate protein levels and certain conditions.
["This test measures alpha-2-macroglobulin in blood and may help evaluate certain liver, kidney, and protein-related conditions."]
Key facts at a glance
- LOINC
- 50176-7
- Short code
- A2 Macroglob MFr SerPl
- Synonyms
- A2 Macroglob MFr SerPl
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- 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?
Alpha-2-macroglobulin is a large protein made by the liver that travels in the blood and helps regulate several substances, including certain enzymes and proteins. This test measures its amount in serum or plasma.
Why might I need this test?
A clinician may order this test as part of an evaluation of liver function, kidney disease, or unusual changes in blood proteins. It may also be used to monitor certain conditions or treatments.
How is the test performed?
A blood sample is collected, and the laboratory measures the amount of alpha-2-macroglobulin in the serum or plasma using an appropriate laboratory method. The test may be reported as a mass concentration or mass fraction depending on the laboratory method.
How do I prepare for the test?
No special preparation is usually required for a routine alpha-2-macroglobulin test. Follow any instructions from your clinician, and tell the laboratory if you are pregnant or have recently received certain treatments that could affect the result.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An unusually low alpha-2-macroglobulin level can occur with some liver conditions, kidney disease, severe illness, or increased loss of protein. A higher level may be associated with certain inflammatory or liver-related conditions and can also be affected by pregnancy and some medications. Results should be interpreted alongside the other parts of your medical evaluation, because this test alone does not establish a diagnosis.
Short name
Alpha-2-Macroglobulin
Frequently asked questions
What does alpha-2-macroglobulin do?
Is this the same as an alpha-1 antitrypsin test?
Do I need to fast for this test?
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