Serum or Plasma Free Light Chain Immunoassay (Quantitative)
This test measures the levels of free light chains (the lighter protein parts of antibodies) in your blood. It helps detect conditions like multiple myeloma, lymphoma, or other immune system disorders.
["Light chains in blood can signal hidden cancers or immune issues."]
Key facts at a glance
- LOINC
- 33129-8
- Short code
- GA from TAD.Hansmann79
- Synonyms
- GA from TAD.Hansmann79
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-estimated-from-tad-hansmann
- 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
Why Is This Test Done?
Your doctor may order this test if you have symptoms like unexplained fatigue, frequent infections, kidney problems, or abnormal blood tests. It’s also used to monitor certain cancers, such as multiple myeloma, or to check for immune system disorders.
What Does the Test Measure?
The test measures two types of free light chains: kappa (κ) and lambda (λ). These are the lighter parts of antibodies that can build up in the blood if the body produces too many antibodies, often seen in conditions like multiple myeloma.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab where it is analyzed using an immunoassay method to detect and measure the free light chains.
What Are the Results?
Results are reported as separate levels for kappa and lambda light chains. High levels of either type can indicate an underlying condition that needs further evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Free light chains are normally present in small amounts in the blood. When levels are elevated, it often signals an overproduction of antibodies, which can be linked to conditions like multiple myeloma, lymphoma, or other plasma cell disorders. These conditions may cause symptoms like bone pain, frequent infections, or kidney problems. Monitoring light chain levels helps doctors diagnose and manage these conditions effectively.
Short name
Free Light Chain Test
Frequently asked questions
What does an elevated free light chain level mean?
How often will I need this test?
Can lifestyle changes affect my light chain levels?
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