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Cerebrospinal Fluid (CSF) Protein by Turbidimetry

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

This test measures the total protein content in your cerebrospinal fluid, which is the fluid surrounding your brain and spinal cord. It helps assess conditions affecting the central nervous system.

Quick summary

["Protein levels in CSF can signal inflammation, bleeding, or other neurological issues."]

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

Key facts at a glance

LOINC
106953-3
Short code
CD123CD19
Synonyms
Cells.CD123+CD19+ NFr Bld FC
Category
chemistry
Sample
whole-blood
Container
EDTA anticoagulant tube (lavender/purple-top, K2-EDTA or K3-EDTA); alternatively, sodium heparin (green-top) tube is acceptable for flow cytometry
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
flow-cytometry
CPT
88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker); 88185 (each additional marker); 88187-88189 (interpretation)
SNOMED
399029000
Specimen volume
3-5 mL of whole blood for adults; minimum 1 mL for pediatric patients
Stability
Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Refrigeration (2-8°C) may extend viability to 48-72 hours but may affect some surface marker expression. Do not freeze.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–48 hours
Order
routine

What Is Cerebrospinal Fluid Protein Used For?

CSF protein testing is often part of a broader evaluation for conditions like meningitis, multiple sclerosis, or brain tumors. High protein levels may indicate inflammation or leakage from blood vessels into the CSF, while low levels could suggest certain genetic disorders or blockages in the brain’s fluid pathways.

When Might You Need This Test?

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, vision changes, or neurological deficits. It’s also used in diagnostic workups for conditions like Guillain-Barré syndrome, Lyme disease, or spinal cord injuries.

How Is the Test Performed?

A small amount of CSF is collected via a lumbar puncture (spinal tap) using a needle inserted into your lower back. The fluid is then sent to the lab for analysis. The test measures protein concentration using turbidimetry, a method that detects cloudiness caused by proteins in the sample.

What Are Common Results and Their Meanings?

Results are typically reported as a concentration (e.g., milligrams per deciliter). Elevated protein levels in CSF may suggest inflammation, infection, or demyelination, while normal or low levels could indicate no significant pathology. Your doctor will interpret results in the context of your symptoms and medical history.

Reference range

Reference ranges vary by laboratory and reporting method. CD123+CD19+ cells (B-lymphocyte subset co-expressing the IL-3 receptor alpha chain CD123) are typically reported as a small subset of peripheral blood B cells. Reported as percentage of lymphocytes or absolute count (cells/µL). Consult laboratory-specific reference intervals.N/A

Specimen: whole-blood

No special patient preparation is required prior to specimen collection. Fasting is not necessary. Patients should be well-hydrated. Inform the laboratory of any recent immunosuppressive therapy, chemotherapy, or corticosteroid use as these may affect lymphocyte subset enumeration.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated CSF protein is often associated with conditions like meningitis, multiple sclerosis, or subarachnoid hemorrhage. It may also appear in chronic inflammatory diseases or certain genetic disorders. Low protein levels can sometimes signal congenital abnormalities in CSF circulation or rare metabolic conditions.

Short name

CSF Protein

Frequently asked questions

Why might my CSF protein test be abnormal?
Abnormal results could be due to infections (e.g., bacterial or viral meningitis), autoimmune diseases (e.g., neuromyelitis optica), or structural issues like arachnoid cysts. Your doctor will review your symptoms, medical history, and possibly additional tests to determine the cause.
How long does it take to get results?
Results are usually available within 24 to 48 hours, depending on lab processing times. If your doctor suspects an urgent condition, they may request results sooner.
Can I prepare for this test?
No special preparation is needed, but avoid heavy exercise or bending for 24 hours before the procedure. Inform your doctor about any medications, especially blood thinners, as they may affect the spinal tap.
  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