Plasma Free Light Chain Immunoassay (Quantitative)
This test measures the levels of free light chains (kappa and lambda) in your plasma, which are protein fragments produced by immune cells. These fragments can help diagnose conditions like multiple myeloma, lymphoma, or other immune-related disorders.
["Light chains help doctors assess immune system health and detect hidden cancers."]
Key facts at a glance
- LOINC
- 101985-0
- Short code
- C parap DNA Fld Ql Probe.amp.tar
- Synonyms
- C parap DNA Fld Ql Probe.amp.tar
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- CPT
- 85610
- SNOMED
- 396252006
- 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 This Test Is Done
Your healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, bone pain, or if tests for other conditions (such as blood cancers) are needed. It may also be used to monitor treatment progress or check for recurrence of conditions like multiple myeloma.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast before the test if it involves a blood draw, but this is not always required for this specific test. Bring any medications you’re taking to your appointment.
How the Test Works
A small amount of blood is drawn from a vein in your arm. The blood is then processed to separate plasma, which is analyzed for free light chains using an immunoassay method to detect and quantify these protein fragments.
What the Results Mean
Results are typically reported as separate levels for kappa and lambda light chains. Elevated levels of one type (or an imbalance between them) may indicate an underlying condition affecting your immune system or blood cells.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal light chain levels can signal conditions such as multiple myeloma, where abnormal plasma cells produce excess light chains. These fragments can also appear in other cancers (like lymphoma) or inflammatory diseases. Monitoring light chains helps guide treatment decisions and track disease progression.
Short name
Free Light Chain Test
Frequently asked questions
What does an abnormal result mean?
Can I eat or drink before this 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