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: Cerebrospinal Fluid Culture, Bacterial

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

: A cerebrospinal fluid (CSF) culture is a laboratory test that attempts to grow and identify bacteria or other microorganisms in a sample of spinal fluid. It helps determine whether an infection such as meningitis is present.

Quick summary

[": A CSF culture checks spinal fluid for germs to help diagnose infections like meningitis."]

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

Key facts at a glance

LOINC
14462-6
Short code
C trach CSF Ql Cult
Synonyms
C trach CSF Ql Cult
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

: What This Test Measures

: CSF is the clear fluid that surrounds and cushions the brain and spinal cord. A culture is performed by placing a small amount of this fluid in special growth media and watching for microorganisms to grow over several days. If organisms grow, the lab identifies them and may test which antibiotics work against them.

: Why It Is Ordered

: Doctors order a CSF culture when they suspect an infection of the membranes or spaces around the brain and spinal cord, such as bacterial meningitis. It is often collected together with cell counts, protein, and glucose measurements on the same sample.

: How the Sample Is Collected

: The spinal fluid is usually obtained by lumbar puncture (a spinal tap), in which a needle is placed in the lower back to draw fluid. The sample is sent to the laboratory promptly, where it is processed and incubated.

: What Results Mean

: A negative culture generally means no bacteria grew, which is reassuring but must be interpreted alongside symptoms and other tests. A positive culture means an organism grew and is identified; susceptibility testing can then guide antibiotic choice. Results should always be discussed with the ordering clinician.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

: CSF Culture

Frequently asked questions

: How long does a CSF culture take?
: Most bacterial growth, if present, appears within one to a few days, but cultures are typically held and observed for several days before being reported as negative. Your care team can tell you when to expect results.
: Does a negative culture rule out infection?
: No. Prior antibiotic use or other factors can prevent organisms from growing even when infection is present. A negative result is interpreted together with symptoms, other spinal fluid tests, and imaging.
: Is the lumbar puncture painful?
: Most people feel a brief sting or pressure during the procedure. Local numbing medicine is often used, and the collection itself usually takes only a short time.
  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