A cerebrospinal fluid (CSF) culture is a laboratory test to look for bacteria, fungi, and viruses in the normally clear fluid that moves in the space around the spinal cord.
Culture - CSF; Spinal fluid culture; CSF culture
How the Test is Performed
A sample of CSF is needed. This sample is usually taken with a lumbar puncture. This is called a spinal tap.
The sample is sent to the laboratory, where it is placed in a special dish (called a culture medium). The laboratory personnel watch to see if bacteria, fungi, or viruses grow in the dish. Growth means there is an infection.
How to Prepare for the Test
For information on how to prepare for the procedure to obtain the CSF sample, see spinal tap.
How the Test Will Feel
For information on how it will feel to have a sample of CSF fluid removed, see spinal tap.
Why the Test is Performed
Your doctor may order this test if you have signs of an infection that affects the brain or nervous system. The test will help identify what is causing the infection. This will help your doctor decide on the best treatment.
A normal result means no bacteria, viruses, or fungi grew in the laboratory dish. This is called a negative result.
What Abnormal Results Mean
If bacteria are present, you may have bacterial meningitis. Other possible infections include tuberculosis and fungal infections. Some bacteria or viruses can also be detected using special tests.
Finding bacteria does not necessarily mean the infection is contagious, unless it is meningococcal meningitis. It may also include:
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.