White Blood Cell Differential Count (Manual Method)
This test measures the types and proportions of white blood cells (WBCs) in your blood, which helps identify infections, immune responses, or other conditions affecting your blood.
["A manual WBC differential helps doctors assess your immune health and diagnose potential blood disorders."]
Key facts at a glance
- LOINC
- 13349-6
- Short code
- WBC # Stl Manual
- Synonyms
- WBC # Stl Manual
- Category
- chemistry
- Sample
- stool
- Container
- Clean container
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 85004
- SNOMED
- 900000000000003002
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if they suspect an infection, inflammation, blood disorder, or immune system issue. It’s often used alongside a complete blood count (CBC) to get a more detailed picture of your blood’s cellular makeup.
What to Expect Before the Test
No special preparation is needed. You’ll likely have a simple blood draw from a vein, usually in your arm. If you’re nervous, let your healthcare provider know—they can help make it more comfortable.
What the Test Measures
The manual differential counts five main types of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type plays a role in fighting infections or responding to inflammation.
How Results Are Interpreted
Results are compared to standard reference ranges to see if your cell counts are within normal limits or if they suggest an underlying condition. For example, high eosinophils might indicate allergies or parasitic infections.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal differentials can signal infections (e.g., high neutrophils), autoimmune diseases (e.g., low lymphocytes), or blood cancers (e.g., unusual basophil counts). It’s a key tool for diagnosing conditions like leukemia, lymphoma, or chronic infections.
Short name
Manual WBC Differential
Frequently asked questions
What causes a manual WBC differential to be ordered?
How long does it take to get results from this test?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 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 16, 2026. · Read our editorial policy