White Blood Cell Differential (Manual Count)
This test measures the types and proportions of white blood cells in your blood, done manually for detailed analysis. It helps identify infections, immune responses, or other blood disorders.
["Understanding your blood’s immune cell balance can reveal hidden health issues."]
Key facts at a glance
- LOINC
- 99051-5
- Short code
- WBC # BAL Manual
- Synonyms
- WBC # BAL Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- 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 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
A white blood cell differential (or manual WBC count) breaks down the five main types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) to assess immune function. This manual method provides precise counts, unlike automated tests that may miss subtle shifts.
What to Expect Before the Test
No special preparation is needed, but avoid strenuous activity or infections 24 hours before testing. Fasted or non-fasted states don’t affect this test.
Common Uses and Conditions
Doctors use this test to diagnose infections (e.g., bacterial vs. viral), autoimmune diseases, leukemia, or allergies. Elevated basophils or eosinophils may signal allergic reactions or parasitic infections.
What the Results Mean
Results show percentages or absolute counts of each cell type. For example, high neutrophils often mean infection, while low lymphocytes may indicate immune suppression.
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 underlying conditions like chronic inflammation, cancer, or immune deficiencies. Your doctor will correlate results with symptoms and other tests for diagnosis.
Short name
WBC Differential (Manual)
Frequently asked questions
How often should I get this test?
What if my results are outside normal ranges?
Can diet or medications affect 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