Blasts, Blood — Manual Count
A laboratory test that identifies and counts blast cells, a type of immature white blood cell, in a peripheral blood sample.
["Detects and counts immature white blood cells in the blood, which can help evaluate unexplained blood-count abnormalities or possible bone marrow disorders."]
Key facts at a glance
- LOINC
- 71669-6
- Short code
- Blasts NFr.DF Bld Manual
- Synonyms
- Blasts NFr.DF 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. Blasts are immature white blood cells that normally develop in the bone marrow before maturing and entering the bloodstream.
Why might I need this test?
A manual blast count may be ordered when a routine complete blood count or blood differential shows unexplained abnormalities. It can help evaluate possible infection, medication effects, or conditions involving the bone marrow and blood-forming cells.
How is the test performed?
A blood sample is collected, usually by drawing blood from a vein. A laboratory specialist reviews a stained blood smear and manually identifies and counts blast cells. Results are often considered along with the rest of the blood count and other laboratory findings.
How do I prepare for the test?
No special preparation is usually required for a routine blood draw. Follow the laboratory's instructions and tell the healthcare professional if you have a bleeding disorder or are taking blood-thinning medicines.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Blasts are generally not present in meaningful numbers in peripheral blood, so an increased count may be important. A higher count can occur with serious infection, certain bone marrow disorders, or the effects of some treatments. The result should be interpreted by a healthcare professional together with symptoms, other blood counts, and additional testing.
Short name
Manual blood blast count
Frequently asked questions
What are blast cells?
Does a manual blast count require a bone marrow sample?
What does an abnormal result mean?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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