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: Cerebral Amyloid Beta Peptide Measurement in Cerebrospinal Fluid

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

: This test measures levels of amyloid beta peptide, a protein fragment, in cerebrospinal fluid, the fluid that surrounds the brain and spinal cord. It is used mainly in research and specialized settings to help evaluate changes associated with Alzheimer disease.

Quick summary

[": CSF amyloid beta measurement provides information about brain amyloid processing and is interpreted by a specialist alongside other clinical and laboratory findings."]

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

Key facts at a glance

LOINC
11701-0
Short code
Fet Cerebral a Middle Vmax sys DOP
Synonyms
Fet Cerebral a Middle Vmax sys DOP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-doppler
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 Being Measured

: Amyloid beta is a protein fragment that comes from a larger protein called amyloid precursor protein. In the brain, these fragments can clump together, and altered levels in cerebrospinal fluid may reflect these processes.

: How the Sample Is Collected

: Cerebrospinal fluid is collected by lumbar puncture, a procedure in which a small amount of fluid is taken from the lower back. The sample is then sent to a laboratory for analysis.

: Why the Test May Be Ordered

: This test is not a routine screening test. It is typically ordered in specialized or research settings, often as part of an evaluation for cognitive changes, and results are interpreted together with symptoms, imaging, and other tests.

: What Results Mean

: Results are usually interpreted in patterns rather than as a single number, and reference ranges vary by laboratory and method. Your care team will explain what the findings mean in your specific situation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

: CSF Amyloid Beta

Frequently asked questions

: Is this a routine blood test?
: No. It measures a protein in cerebrospinal fluid obtained by lumbar puncture and is used mainly in specialized or research settings.
: Can this test diagnose Alzheimer disease by itself?
: No. It is one piece of information and must be interpreted by a specialist alongside symptoms, imaging, and other evaluations.
: Does a normal result rule out memory problems?
: No. Many factors can affect thinking and memory, and a single laboratory result does not rule out or confirm any condition.
  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