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Blast Cells, Nonfractionated Whole Blood — Manual Count

Published: August 9, 2026Updated: August 17, 2026

A manual count estimates blast cells, an immature type of white blood cell, in a blood sample to help evaluate possible blood cancers and monitor treatment.

Quick summary

["Detected or increased blast cells may indicate a blood or bone marrow disorder and usually require further testing."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
709-6
Short code
Blasts NFr Bld Manual
Synonyms
Blasts NFr Bld Manual
Category
liver
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
CPT
84484
SNOMED
302774002
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test examines a blood sample for blast cells, which are immature white blood cells that have not yet fully matured. A laboratory technologist reviews a stained blood smear under a microscope and estimates the number of blasts present.

Why might I need this test?

A blast cell count may be ordered when unexplained blood counts, symptoms such as fatigue, bruising, fever, or weight loss raise concern for a blood cancer. It may also be used to monitor leukemia, lymphoma, or treatment response.

How is the test performed?

A technologist prepares and reviews a peripheral blood smear under a microscope, identifying and counting or estimating blast cells as part of the blood differential. Abnormal findings may lead to additional tests, such as flow cytometry or bone marrow testing.

How do I prepare for the test?

This test generally requires no fasting or special preparation. Follow your clinician's instructions about timing, medications, and any other blood tests that may be ordered with it.

Reference range

Adult: 10-40 U/LN/A

Specimen: whole-blood

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Blood Blast Cell Count

Frequently asked questions

What are blast cells?
Blast cells are immature white blood cells that normally develop into mature immune cells in the bone marrow. Finding many blasts in the blood can be a sign of a blood or bone marrow disorder.
Does an abnormal result mean I have cancer?
No. An abnormal result does not diagnose cancer by itself and must be considered with other blood tests, symptoms, and medical history. Your clinician may recommend further testing to determine the cause.
Is this the same as a complete blood count?
A complete blood count measures the numbers of major blood cell types, while this manual review specifically identifies and estimates blasts. The blast assessment is often performed as part of the blood differential.
  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 17, 2026. · Read our editorial policy