Red Blood Cell Count (with Differential Count)
This test measures the types and proportions of cells found in your blood, including red blood cells, white blood cells, and platelets. It helps identify infections, blood disorders, or other health conditions.
["Understanding your blood cell composition can reveal hidden health issues."]
Key facts at a glance
- LOINC
- 33586-9
- Short code
- CD2CD7
- Synonyms
- CD2+CD7+ Cells # Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA) or ACD-A anticoagulant tube for flow cytometry immunophenotyping
- Units
- N/A
- Ref low
- 80
- Ref high
- 95
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–999 years
- Method
- Flow cytometry using fluorescently labeled monoclonal antibodies against CD2 and CD7 surface markers, with absolute counting performed via dual-platform (CD45 gating with internal calibrator beads) or single-platform bead-based methodology
- CPT
- 86359
- SNOMED
- 269849007
- Specimen volume
- 3-5 mL of whole blood in EDTA tube; minimum 1 mL for pediatric samples
- Stability
- Ambient temperature: 18-24 hours; refrigerated (2-8°C): up to 48 hours. Specimen should not be frozen. Process within 24 hours for optimal cell viability and antigen expression.
- Hemolysis max
- 100
- Lipemia max
- 300
- TAT
- 24–72 hours
- Order
- routine
What Does the Test Measure?
Your blood sample is analyzed to count and classify different cell types. This includes red blood cells (RBCs), white blood cells (WBCs) broken down into subtypes (neutrophils, lymphocytes, etc.), and platelets. The results help determine if your blood contains too few or too many of any specific cell type.
Why Might You Need This Test?
Doctors may order this test to diagnose or monitor conditions like anemia, infections, blood cancers, or immune disorders. It’s also used before surgeries or treatments that could affect your blood count.
How Is the Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The sample is then processed in a lab to count and identify the different cell types. This is a quick and painless procedure, often done in a doctor’s office or lab.
What Are Common Findings?
Results may show elevated or low counts of specific cell types, which can signal infections, inflammatory diseases, or blood disorders. For example, a high neutrophil count might indicate infection, while a low lymphocyte count could suggest immune problems.
Reference range
Reference ranges vary by laboratory and age; CD2+ and CD7+ T-lymphocyte subsets generally comprise the majority of peripheral T-cells (CD2: ~80-95%, CD7: ~75-90% of total lymphocytes). Absolute counts should be interpreted using laboratory-specific reference intervals established for age-matched controls.N/A
No fasting required. Patients should avoid strenuous exercise prior to collection. Specimen should be processed promptly (within 24-48 hours) to maintain cell viability. Inform the laboratory of any recent immunomodulatory therapy, chemotherapy, or immunosuppressive medications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test plays a critical role in diagnosing and managing conditions affecting blood cell production or function. Abnormal results can prompt further testing or adjustments to treatment plans, such as medications or lifestyle changes.
Short name
RBC Differential (Cells in Blood)
Frequently asked questions
What does a ‘cells in blood’ test tell me about my health?
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