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Beta2transferrinpnlserplcsf

Published: August 9, 2026Updated: August 17, 2026

A specialized test to detect whether fluid leaking from the nose or ear is cerebrospinal fluid (CSF).

Quick summary

{"Beta-2 transferrin is a protein found only in CSF, not in blood or nasal secretions","This test helps diagnose cerebrospinal fluid (CSF) leaks, often after head injury or surgery","Fluid samples from the nose, ear, or surgical site are collected and analyzed","Results help guide treatment decisions for skull base defects or cranial surgeries"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
77347-3
Short code
B2T
Synonyms
Beta-2 transferrin Pnl SerPl+CSF
Category
chemistry
Sample
csf
Container
Sterile CSF collection tube for CSF; SST (serum separator tube) or PST (plasma separator tube) for serum/plasma; sterile leak-proof container for nasal or ear fluid
Units
N/A
Ref low
200
Ref high
350
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Immunofixation Electrophoresis / Western Blot
CPT
82784
SNOMED
104002009
Specimen volume
1 mL CSF; 1 mL serum or plasma; minimum 0.5 mL for nasal/ear fluid
Stability
CSF: 2-8°C for up to 7 days; frozen at -20°C for longer storage. Serum/Plasma: 2-8°C for up to 7 days. Do not use hemolyzed or contaminated specimens.
Hemolysis max
200
TAT
24–72 hours
Order
routine

What is this test?

The Beta-2 Transferrin test is a specialized laboratory test that identifies the presence of beta-2 transferrin, a unique protein found almost exclusively in cerebrospinal fluid (CSF). CSF is the clear fluid that surrounds the brain and spinal cord. This test is primarily used to determine whether fluid leaking from the nose (rhinorrhea) or ear (otorrhea) is actually CSF, which helps diagnose conditions like CSF leaks or skull base defects.

How is the test performed?

A sample of the suspicious fluid is collected from your nose, ear, or any other site where fluid is draining. In some cases, a comparison sample of blood (serum) may also be collected. The fluid samples are then sent to a laboratory where they are analyzed using specialized techniques to detect the presence of beta-2 transferrin. The test looks for this specific protein marker that indicates the fluid is cerebrospinal fluid rather than mucus, blood, or other body fluids.

Why is this test ordered?

Your healthcare provider may order this test if you have clear fluid dripping from your nose or ears, especially after a head injury, sinus surgery, brain surgery, or if you have conditions that might cause CSF leaks. Identifying a CSF leak is important because it can lead to serious complications such as meningitis (brain infection) if left untreated. This test helps confirm the diagnosis so appropriate treatment can be initiated.

Reference range

NCBI: Transferrin 200-350 mg/dLN/A

Specimen: csf

No special patient preparation is required. For suspected CSF rhinorrhea or otorrhea, collect the fluid (nasal or ear discharge) in a sterile container and submit alongside a serum or plasma sample for comparison.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is the test painful?
The test itself is not painful. It only requires collecting a sample of the draining fluid. Your healthcare provider will gently collect the fluid using a swab or container. If a blood sample is needed, you may feel a brief sting from the needle.
How long does it take to get results?
Results typically take 1-3 days, as the test requires specialized laboratory analysis. Your healthcare provider will contact you with the results once they are available.
What do the results mean?
A positive result means beta-2 transferrin was detected in the fluid sample, confirming that the fluid is cerebrospinal fluid. A negative result means the fluid is likely not CSF (it may be mucus, blood, or another fluid). Your doctor will interpret these results in the context of your symptoms and medical history.
Do I need to prepare for this test?
No special preparation is needed. Simply inform your healthcare provider about any medications you are taking and any recent head injuries or surgeries. Avoid blowing your nose or manipulating the drainage site before sample collection if possible.
  1. 1
    Mayo Clinic Laboratories - Beta-2 Transferrin, Spinal FluidSource
  2. 2
    Cleveland Clinic - Cerebrospinal Fluid (CSF) LeakSource
  3. 3
    Stanford Health Care - CSF RhinorrheaSource

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 17, 2026. · Read our editorial policy