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Protein Electrophoresis (Serum/Plasma) with Free Light Chains

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

This test measures the different types of proteins in your blood, focusing on the free light chains—small protein fragments that can indicate certain health conditions.

Quick summary

["Helps diagnose and monitor conditions like multiple myeloma or other blood disorders by detecting abnormal protein levels."]

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

Key facts at a glance

LOINC
87557-5
Short code
Prot S Ag + Prot S Ag.free Pnl PPP IA
Synonyms
Prot S Ag + Prot S Ag.free Pnl PPP IA
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
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

What This Test Measures

Protein electrophoresis separates blood proteins into distinct bands, revealing the presence and concentration of various protein types. Free light chains are specifically analyzed to identify fragments that may signal underlying disorders, such as multiple myeloma or other plasma cell dyscrasias.

Why It’s Done

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, bone pain, or kidney issues. It’s also used to monitor known conditions affecting protein production or breakdown.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The blood is processed to separate serum or plasma, which is then analyzed using electrophoresis to detect protein patterns and free light chains.

Common Conditions Monitored

Abnormal results may point to conditions like multiple myeloma (a cancer of plasma cells), light chain amyloidosis, or other disorders disrupting normal protein balance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High or abnormal levels of free light chains can indicate plasma cell disorders, kidney problems, or other systemic diseases. Low or unusual patterns may require further investigation to rule out hidden health risks.

Short name

Protein Electrophoresis (Free Light Chains)

Frequently asked questions

What does a ‘positive’ or abnormal result mean?
An abnormal result may suggest an underlying condition affecting protein production or kidney function. Your doctor will discuss findings and next steps based on your symptoms and medical history.
How often will I need this test?
Frequency depends on your diagnosis or treatment plan. Some patients need it monthly, while others may only need it occasionally. Follow your provider’s instructions.
Can I eat or drink before this test?
Typically, no special diet is required, but always check with your lab or doctor for specific instructions, as some tests may have fasting guidelines.
  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