Basophilscsfqlmicro
This test checks for the presence of basophils, a type of white blood cell, in the fluid surrounding your brain and spinal cord.
{"Basophils are normally not found in cerebrospinal fluid (CSF)","Their presence may indicate inflammation, infection, or other medical conditions","The test uses a microscope to examine a CSF sample collected via lumbar puncture","Results help doctors diagnose and monitor certain neurological conditions","This is a specialized test often ordered when specific brain or spinal cord issues are suspected"}
Key facts at a glance
- LOINC
- 44040-4
- Short code
- CSF BASO
- Synonyms
- Basophils CSF Ql Micro
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube (tube 3 or 4 preferred for cell count to minimize blood contamination from traumatic tap)
- Units
- N/A
- Ref low
- 0
- Ref high
- 0
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- CPT
- 89051
- SNOMED
- 165356004
- Specimen volume
- 1-2 mL of cerebrospinal fluid
- Stability
- Analyze within 1 hour of collection for optimal cell morphology. If delayed, refrigerate at 2-8°C and analyze within 4 hours. CSF cells degrade rapidly.
- Hemolysis max
- 200
- TAT
- 1–4 hours
- Order
- routine
What is this test?
The Basophils in CSF test is a laboratory examination that looks for the presence of basophils in your cerebrospinal fluid (CSF). CSF is the clear, protective fluid that surrounds your brain and spinal cord. Basophils are a type of white blood cell that play a role in your body's immune response. Under normal circumstances, basophils are not typically found in cerebrospinal fluid.
How is the test performed?
A healthcare provider will collect a sample of your cerebrospinal fluid through a procedure called a lumbar puncture (spinal tap). During this procedure, a thin needle is inserted into the lower back to draw out CSF. The sample is then sent to a laboratory where it is examined under a light microscope to check for the presence of basophils and other cells.
What do the results mean?
A normal result typically shows no basophils in the CSF. If basophils are detected, it may indicate an underlying condition that is causing inflammation or an immune response in the central nervous system. Your doctor will interpret these results along with other test findings and your symptoms to determine the cause.
Reference range
Normally absent or rare in CSF. Basophils are not typically present in cerebrospinal fluid under normal physiologic conditions. Any detectable basophils should be correlated with clinical findings.N/A
No fasting required. Lumbar puncture should be performed under sterile conditions. Patient should remain still during the procedure. Inform physician of any bleeding disorders, anticoagulant use, or skin infection at the puncture site.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Why would my doctor order this test?
Is the lumbar puncture procedure painful?
How long does it take to get results?
Are there any risks associated with this test?
Sources
- 1
- 2
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.
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