Serum or Plasma Free Light Chain Immunoassay (Quantitative)
This test measures the levels of free light chains (kappa or lambda) in your blood, which can help diagnose conditions affecting plasma cells, such as multiple myeloma or other monoclonal gammopathies.
["Light chains help identify abnormal protein production in your blood."]
Key facts at a glance
- LOINC
- 106608-3
- Short code
- S pyo DNA Fld Ql NAA+n-prb
- Synonyms
- S pyo DNA Fld Ql NAA+n-prb
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- non-probe-amp-tar
- 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 healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, bone pain, or kidney problems. It’s also used to monitor conditions like multiple myeloma, lymphoma, or other blood disorders that involve abnormal protein production in plasma cells.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on blood thinners, let your provider know before the test.
What the Test Results Mean
High levels of free light chains may indicate conditions like multiple myeloma, where plasma cells produce too many abnormal proteins. Low or normal levels are usually within expected ranges, but results depend on your medical history and symptoms.
Common Conditions Monitored
This test helps diagnose and monitor conditions such as multiple myeloma, Waldenström macroglobulinemia, and other monoclonal gammopathies. It may also be used in patients with kidney disease or unexplained anemia.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Free light chains are small protein fragments produced by plasma cells. When plasma cells become abnormal (e.g., in multiple myeloma), they may overproduce these light chains, which can accumulate in the blood and affect organs like the kidneys. Elevated levels can signal disease activity and guide treatment decisions.
Short name
Free Light Chain Test
Frequently asked questions
What causes abnormal light chain levels?
Will I need to avoid certain foods or medications before the test?
How long will it take to get my results?
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