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Serum or Plasma Free Light Chain Immunoassay (Quantitative)

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

This test measures the levels of free light chains (kappa and lambda) in your blood, which are protein fragments produced by plasma cells. These fragments can help diagnose conditions like multiple myeloma, lymphoma, or other immune system disorders.

Quick summary

["Light chains help identify blood cancers and immune disorders by detecting abnormal protein fragments in your bloodstream."]

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

Key facts at a glance

LOINC
56598-6
Short code
EBV EA IgM Ser IA-aCnc
Synonyms
EBV EA IgM Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 Might Be Ordered

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, bone pain, frequent infections, or if tests for conditions like multiple myeloma or lymphoma are needed. It’s also used to monitor treatment progress or check for recurrence of these diseases.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm 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 abnormal plasma cells produce too many light chains. Low or normal levels are usually fine, but your provider will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

This test is often used to diagnose or monitor multiple myeloma, lymphoma, or other plasma cell disorders. It can also help track how well treatments are working or if disease spreads to other parts of the body.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Free Light Chains

Frequently asked questions

What does an abnormal result mean?
An elevated result may suggest an underlying condition like multiple myeloma, where abnormal plasma cells produce excessive light chains. Your provider will review the full picture, including other tests and symptoms, to determine the cause.
Can this test be done at home?
No, this test requires a blood sample drawn in a clinical setting by a healthcare professional.
How often should I get this test?
Your provider will determine the frequency based on your diagnosis, treatment plan, or symptoms. Follow their instructions closely for follow-up testing.
  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