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Qualitative Detection of White Blood Cells in Whole Blood (Peripheral Smear)

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

This test checks if your blood contains abnormal numbers of white blood cells, which can signal infections, inflammation, or other health issues.

Quick summary

["It helps identify whether your immune system or blood health may need closer monitoring."]

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

Key facts at a glance

LOINC
46996-5
Short code
Num HLA Ab positive cells
Synonyms
Num HLA Ab positive cells
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

What This Test Measures

A small sample of your blood is spread thinly on a microscope slide. A healthcare provider examines it under a microscope to count and identify different types of white blood cells. This is a qualitative (not quantitative) test, meaning it only tells you if cells are present or absent, not their exact numbers.

How the Test Is Performed

No special preparation is needed. A healthcare professional will draw blood from a vein, usually in your arm. The blood sample is then prepared and examined for white blood cells under a microscope.

Why It Might Be Ordered

Your doctor may recommend this test if you have symptoms like fever, fatigue, unexplained weight loss, frequent infections, or if they suspect conditions like leukemia, lymphoma, or other blood disorders.

Possible Results and Interpretation

The result will indicate whether white blood cells are present in abnormal amounts. If the test shows an unusual number of cells, further testing may be needed to determine the cause.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test is critical for diagnosing conditions affecting white blood cell counts, such as infections, autoimmune diseases, or blood cancers. Abnormal findings prompt additional evaluation to guide treatment decisions.

Short name

WBC Qualitative Blood Smear

Frequently asked questions

What does a positive result mean?
A positive result means white blood cells are detected in the blood sample, which may indicate an infection, inflammation, or other underlying health issue. Your doctor will discuss this with you and may order further tests.
Can I prepare for this test?
No special preparation is needed. However, inform your doctor about any medications or conditions that might affect blood results.
How long will it take to get results?
Results are typically available within a few days, depending on lab processing times. Your doctor will contact you with the findings.
  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