Serum or plasma free light chains (total)
This test measures the free light chains (the smaller protein parts) released by plasma cells, which can help identify certain blood disorders.
["Free light chains may signal conditions like multiple myeloma or other plasma cell diseases."]
Key facts at a glance
- LOINC
- 7315-5
- Short code
- Flea BasoBnd Ab Qn
- Synonyms
- Flea BasoBnd Ab Qn
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- lhr
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What Is This Test Measuring?
Free light chains are protein fragments produced by plasma cells, which are white blood cells involved in making antibodies. When these cells become abnormal (e.g., in multiple myeloma), they release excessive free light chains into the blood. This test detects the total amount of these free light chains in your serum or plasma sample.
Why Might You Need This Test?
Doctors may order this test to monitor or diagnose conditions such as multiple myeloma, lymphoma, or other plasma cell disorders. It can also help track treatment progress or detect early signs of disease recurrence.
How Is the Sample Collected?
A blood sample is drawn from a vein, usually in your arm. The blood is then separated to obtain either serum (after clotting) or plasma (anticoagulated blood). The free light chains are measured from this sample using a specialized laboratory technique.
What Are Common Uses?
This test is primarily used in the evaluation and management of hematologic (blood-related) disorders. It may be part of a broader panel to assess bone marrow function, kidney health, or other systemic conditions linked to abnormal plasma cell activity.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated free light chains can indicate overproduction by plasma cells, which is characteristic of multiple myeloma or other monoclonal gammopathies. Uneven levels of kappa and lambda free light chains (measured separately) can also help differentiate between benign conditions and serious diseases. Kidney function may be monitored alongside this test due to potential nephrotoxicity from certain treatments.
Short name
Total Free Light Chains
Frequently asked questions
What Does a High or Low Level Mean?
How Often Should I Get This Test?
Can Diet or Supplements Affect 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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy