Understanding Your Laboratory Test: What It Is, How It Is Performed, and What Your Results Mean
This test detects the presence of basophils (a type of white blood cell) in body fluid using microscopic examination.
{"Basophils are white blood cells that play a role in immune response","The test uses microscopy to detect basophils in fluid samples","Results help diagnose infections, allergic reactions, or blood disorders","Sample is typically collected via fluid aspiration","Results are interpreted in context with other test findings"}
Key facts at a glance
- LOINC
- 44018-0
- Short code
- BASO BF
- Synonyms
- Basophils Fld Ql Micro
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container appropriate for the specific body fluid type (e.g., sterile screw-cap tube, EDTA tube for cell preservation). For cerebrospinal fluid, use sterile collection tubes in numbered sequence.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- CPT
- 89051
- SNOMED
- 39106-0
- Specimen volume
- Minimum 1-2 mL of body fluid; volume requirements vary based on fluid type and laboratory protocols.
- Stability
- Specimen should be analyzed as soon as possible, preferably within 1 hour of collection for optimal cell morphology preservation. If delayed, refrigerate at 2-8°C and analyze within 4 hours.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
This test is a laboratory analysis that helps your healthcare provider screen for certain conditions, monitor an ongoing illness, or check how well a treatment is working. It measures specific substances in your body and gives your care team objective information that supports an accurate diagnosis and a personalized care plan.
The Basophils Presence test is a laboratory examination that uses light microscopy to detect and identify basophils in a body fluid sample. Basophils are a type of white blood cell (leukocyte) that are part of your immune system and play a key role in defending your body against infections and allergic reactions.
A trained healthcare professional will collect the sample, which may be a small amount of blood drawn from a vein in your arm, a urine specimen, or a swab from the affected area, depending on what the test requires. The procedure is usually quick, causes only minor discomfort, and you can normally return to your everyday activities right afterward.
The fluid sample is collected through a procedure called fluid aspiration, where a healthcare provider uses a needle to withdraw fluid from a specific body area (such as synovial fluid, pleural fluid, or other body cavities). The type of fluid collected depends on your symptoms and the area being examined.
Your results are compared with established reference ranges to show whether your values fall within the expected limits. Readings that are higher or lower than normal may suggest a specific condition, but they rarely provide a diagnosis on their own. Your healthcare provider will interpret the findings together with your symptoms, medical history, and other test results, so always review your report with them before drawing conclusions.
The presence or absence of basophils in the fluid sample is reported. Normally, basophils are not present in most body fluids. If basophils are detected, it may indicate an underlying condition that requires further evaluation. Your healthcare provider will interpret these results along with your other test results and clinical symptoms.
Reference range
Basophils are typically absent or rarely seen in normal body fluids. Presence is reported as rare, occasional, few, moderate, or many; quantitative reference values are not well established and depend on the specific body fluid source.N/A
No special patient preparation required prior to specimen collection. Fasting is not required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated basophils in body fluid may indicate: allergic or inflammatory reactions, certain infections, or hematologic conditions. The absence of basophils in most cases is considered normal. This test helps healthcare providers diagnose and monitor conditions affecting the immune system and blood. Results should always be interpreted by your healthcare provider in the context of your complete medical history and other diagnostic findings.
Frequently asked questions
Do I need to fast before this test?
Is this test painful?
How long does it take to get results?
What should I do if my results are abnormal?
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