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Myeloblasts, Peripheral Blood — Manual Count

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

A manual microscopic count of myeloblasts in a stained peripheral blood smear, usually performed as part of a blood count with differential.

Quick summary

["An increased myeloblast count may indicate a bone marrow disorder, including acute myeloid leukemia, and should be reviewed promptly by a clinician."]

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

Key facts at a glance

LOINC
747-6
Short code
Myeloblasts NFr Bld Manual
Synonyms
Myeloblasts 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 counts myeloblasts, which are immature white blood cell precursors, on a peripheral blood smear. It is usually reviewed as part of a complete blood count with differential.

Why might I need this test?

A clinician may order this test to investigate unexplained changes in blood counts, unexplained bruising or bleeding, fatigue, fever, or other symptoms suggesting a blood or bone marrow disorder.

How is the test performed?

A blood sample is collected, and a thin layer of blood is stained and examined under a microscope. A laboratory professional manually identifies and counts myeloblasts among the white blood cells.

How do I prepare for the test?

No special preparation is usually needed, and fasting is generally not required. Follow any instructions provided by the ordering clinician or the laboratory.

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

Peripheral blood myeloblast count

Frequently asked questions

What does an elevated myeloblast count mean?
It may indicate that abnormal immature white blood cells are entering the bloodstream, which can occur with leukemia or other bone marrow conditions. The finding does not identify the cause by itself.
Does this test diagnose leukemia?
No. An abnormal result can raise concern for leukemia, but diagnosis generally requires additional blood tests, examination of the bone marrow, and other clinical findings.
Do I need to fast before this test?
Fasting is usually not necessary. If the test is being performed for a specific medical reason, follow the instructions given by your healthcare professional.
  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