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Blast Cells, Peripheral Blood — Flow Cytometry, Number Fraction

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

Measures the proportion of immature blast cells in peripheral blood and may characterize their cell-surface markers.

Quick summary

["This test can help detect and identify abnormal immature white blood cells that may be associated with a blood disorder."]

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

Key facts at a glance

LOINC
107079-6
Short code
Blasts NFr Bld FC
Synonyms
Blasts NFr Bld FC
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
flow-cytometry
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 blood test measures blast cells, which are immature forms of white blood cells. Flow cytometry may also examine specific markers on the cells to help classify them.

Why might I need this test?

Your clinician may order it when a blood count or blood smear shows an unexplained increase in immature cells, or when a blood disorder such as leukemia is suspected.

How is the test performed?

A venous blood sample is collected and analyzed by flow cytometry. The laboratory determines the proportion of blast cells and may evaluate their characteristic cell-surface markers.

How do I prepare for the test?

Fasting is generally not required for this test. Follow your clinician's instructions, and tell the laboratory if you recently received chemotherapy, a stem cell transplant, or certain medications that may affect blood-cell findings.

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 cells by flow cytometry

Frequently asked questions

Are blast cells always a sign of cancer?
No. Blast cells are immature white blood cells, and their presence in peripheral blood can have several causes. A clinician must interpret the result with your blood count, smear, medical history, and other tests.
Does this test diagnose leukemia by itself?
No. Flow cytometry can identify and characterize abnormal blast cells, but a leukemia diagnosis generally requires additional testing, often including a bone marrow examination.
Can I take the test without fasting?
Yes, fasting is usually unnecessary unless your clinician gives different instructions. The blood sample can generally be collected during a routine clinic visit.
  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