Skip to content

White Blood Cell Differential with Other Granulocyte Fractions (Quantitative)

Published: August 9, 2026Updated: August 16, 2026

This test measures the types and proportions of white blood cells in your blood, including detailed breakdowns of neutrophils, eosinophils, basophils, and other granulocyte subtypes. It helps assess immune function, infection risk, or inflammatory conditions.

Quick summary

["Understanding your granulocyte counts can help diagnose or monitor blood disorders or infections."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30409-7
Short code
WBC Other NFr Prt
Synonyms
WBC Other NFr Prt
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
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 Is Done

Doctors may order this test to evaluate immune responses, identify infections, or check for conditions like leukemia, autoimmune diseases, or allergies. It’s often used alongside a complete blood count (CBC) for a more detailed picture of your blood’s cellular makeup.

What to Expect Before the Test

No special preparation is needed, but avoid heavy meals or strenuous activity 24 hours before testing. If you’re on medications that affect white blood cells (e.g., steroids), let your provider know.

Common Conditions Monitored

This test helps track conditions like chronic infections, inflammatory diseases (e.g., rheumatoid arthritis), or blood cancers. Elevated or low granulocyte counts may signal underlying issues requiring further investigation.

What the Results Mean

Results show percentages and absolute counts of granulocytes. Abnormal levels (e.g., high eosinophils in allergies or low neutrophils in infections) may prompt additional testing or treatment adjustments.

Reference range

Adult: 4.5-11.0 x 10^9/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

WBC Differential (Extended Granulocyte Analysis)

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–2 business days, depending on lab processing times. Follow-up with your provider to discuss findings.
Can diet or exercise affect these results?
Moderate diet or exercise usually doesn’t impact granulocyte counts. However, severe stress, illness, or recent infections may temporarily alter results—discuss with your provider if concerned.
Do I need to fast before this test?
No fasting is required. Unlike some blood tests, diet doesn’t interfere with granulocyte analysis.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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