Red Blood Cell Count with Differential (Blood Cell Count with Differential Count)
This test measures the number and types of cells in your blood, including red blood cells, white blood cells, and platelets, along with the proportions of different white blood cell types.
["Understanding your blood cell composition helps diagnose conditions like infections, anemia, or blood disorders."]
Key facts at a glance
- LOINC
- 26572-8
- Short code
- CD2CD7
- Synonyms
- CD2+CD7+ Cells NFr Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA (lavender/purple top) or ACD (yellow top) anticoagulant tube
- Units
- N/A
- Ref low
- 70
- Ref high
- 85
- Critical range
- 5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Flow cytometry using fluorescently labeled monoclonal antibodies (CD2-FITC and CD7-PE) with whole blood lysis technique, analyzed on a flow cytometer
- CPT
- 86359
- SNOMED
- 399080001
- Specimen volume
- 3-5 mL of whole blood; minimum 1 mL for pediatric samples
- Stability
- Process within 24-48 hours of collection when stored at room temperature (18-25°C); do not refrigerate as this can affect cell viability and marker expression. For delays beyond 48 hours, consult laboratory guidelines.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
Why This Test Is Done
Doctors order a blood differential to check for infections, blood disorders, or other health issues. It helps identify abnormal cell counts that might indicate conditions such as leukemia, anemia, or immune system problems.
What to Expect Before the Test
You can eat and drink normally before this test. No special preparation is needed, but inform your doctor about any medications you’re taking, as some may affect results.
What the Test Involves
A small blood sample is taken from a vein in your arm using a needle. The sample is then analyzed to count and classify different blood cells.
What the Results Mean
Results show absolute counts of each cell type and their relative percentages. Abnormal counts may signal infections, cancers, or other health concerns that need further evaluation.
Reference range
CD2+CD7+ cells represent a subset of T-lymphocytes; reference ranges vary by laboratory. Typical values: 70-85% of total lymphocytes (percentage) or 1100-1700 cells/µL (absolute count)N/A
No fasting required. Patients should be well-hydrated. Recent immunizations, infections, immunosuppressive therapy, or chemotherapy may affect lymphocyte subset populations. Inform laboratory of relevant clinical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A blood differential is critical for diagnosing conditions like infections (e.g., bacterial or viral), blood cancers (e.g., leukemia), autoimmune diseases, or anemia. Changes in white blood cell counts (e.g., high or low neutrophils) often point to underlying issues requiring medical attention.
Short name
RBC Differential
Frequently asked questions
What does a blood differential test measure?
How long does it take to get results from this test?
Can I eat or drink before this test?
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 15, 2026. · Read our editorial policy