Basophilsnfrdfbldauto
A blood test that measures the percentage of basophils, a type of white blood cell, in your total white blood cell count.
{"Basophils are white blood cells that help your body fight infections and respond to allergens","This test is usually part of a complete blood count (CBC) with differential","Results are expressed as a percentage of total white blood cells","Abnormal levels may indicate allergies, infections, or certain blood disorders"}
Key facts at a glance
- LOINC
- 71680-3
- Short code
- BASO%
- Synonyms
- Basophils NFr.DF Bld Auto
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA (lavender/purple-top) vacuum blood collection tube; K2-EDTA or K3-EDTA acceptable
- Units
- N/A
- Ref low
- 0.5
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- automated-count
- CPT
- 85004 (automated CBC with automated differential WBC count)
- SNOMED
- 304682000
- Specimen volume
- 1-3 mL of whole blood; minimum 0.5 mL required for pediatric or microtainer samples
- Stability
- Room temperature (18-25°C): up to 24 hours; Refrigerated (2-8°C): up to 48 hours. Best results within 4 hours of collection.
- Hemolysis max
- 100
- Lipemia max
- 300
- Icterus max
- 25
- TAT
- 1–4 hours
- Order
- routine
What is this test?
The basophil count test measures the percentage of basophils in your blood. Basophils are the least common type of white blood cell, making up less than 1% of all white blood cells. They play an important role in your immune system by releasing histamine during allergic reactions and helping to fight certain infections.
Why do I need this test?
Your doctor may order this test as part of a complete blood count (CBC) with differential to check your overall health. It can help diagnose conditions such as allergic reactions, infections, inflammatory diseases, and certain blood disorders like leukemia. The test may also be used to monitor your response to certain treatments.
How is the test performed?
A healthcare professional will draw a small blood sample from a vein in your arm using a needle. The sample is then sent to a laboratory where an automated analyzer counts and classifies the different types of white blood cells, including basophils. The result is reported as a percentage (fraction) of your total white blood cell count.
What do the results mean?
Normal basophil percentage is typically less than 1% of total white blood cells. Elevated levels (basophilia) may indicate allergic reactions, infections, inflammatory conditions, certain leukemias, or other disorders. Low levels (basopenia) are less common and may occur during pregnancy, hyperthyroidism, or as a side effect of certain medications.
Reference range
Adults: 0.5-1.0% of total leukocytes (relative); Absolute count: 0.02-0.10 x 10^3/uL (20-100 cells/uL). Reference ranges vary slightly by laboratory, instrument, and population.N/A
No special patient preparation required. Fasting is not necessary. Patient should be relaxed as stress and exercise can transiently affect basophil distribution.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Are there any risks from this test?
What can cause high basophil levels?
What can cause low basophil levels?
Will I need follow-up testing?
Sources
- 1
- 2
- 3
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 10, 2026. · Read our editorial policy