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Genetic analysis of cerebrospinal fluid (CSF) for neurofilament light chain (NfL) mass concentration

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

This test measures the level of neurofilament light chain (NfL) in your cerebrospinal fluid. NfL is a protein found in nerve cells and can help assess nerve damage or disease.

Quick summary

["NfL levels in CSF may indicate nerve cell injury, useful in conditions like traumatic brain injury or neurodegenerative diseases."]

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

Key facts at a glance

LOINC
19102-3
Short code
Genetic scn Spec
Synonyms
Genetic scn Spec
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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 Is Neurofilament Light Chain (NfL)?

NfL is a protein that makes up the cytoskeleton of nerve cells. When nerve fibers are damaged, NfL can be released into the cerebrospinal fluid (CSF). Measuring NfL helps doctors evaluate the extent of nerve injury or disease progression in conditions such as multiple sclerosis, traumatic brain injury, or other neurological disorders.

Why Might This Test Be Ordered?

Your healthcare provider may recommend this test if you have symptoms or a history suggestive of nerve damage, such as persistent headaches, cognitive changes, or neurological symptoms. It may also be used to monitor disease activity in conditions affecting the central nervous system.

How Is the Test Performed?

A small amount of cerebrospinal fluid is collected through a procedure called a lumbar puncture (spinal tap). The fluid is then analyzed in a laboratory to measure NfL levels.

What Are Common Uses?

This test is primarily used to assess nerve cell damage or disease activity in neurological conditions. It can help guide treatment decisions or monitor disease progression over time.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

NfL CSF Profile

Frequently asked questions

What does a high or low NfL level mean?
A high NfL level may suggest nerve damage or disease activity, while a low level may indicate less nerve injury. Your results will be discussed with your doctor to determine the next steps.
How long does it take to get results?
Test results are typically available within 1 to 3 business days, depending on laboratory processing times.
Is this test painful?
The lumbar puncture procedure may cause mild discomfort, but most patients describe it as similar to receiving a deep injection. You may experience temporary soreness or a mild headache afterward.
  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