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Reticulocyte Count with Calculation of Absolute Reticulocyte Count (ARC)

Published: August 9, 2026Updated: August 16, 2026

This test measures your blood’s immature red blood cells (reticulocytes) to assess bone marrow activity and red blood cell production.

Quick summary

["Helps doctors check if your bone marrow is making enough healthy red blood cells."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
42758-3
Short code
Retics # Calc
Synonyms
Retics # Calc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
calculated
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

Why This Test Matters for Your Health

Reticulocytes are young red blood cells released from your bone marrow to replace older ones. Measuring them helps diagnose conditions like anemia, blood loss, or overactive bone marrow (e.g., from chemotherapy or certain cancers).

How the Test Works

Blood is drawn, and reticulocytes are counted directly (qualitative) and then adjusted for your total red blood cell count to calculate the absolute reticulocyte count (ARC). This number helps determine if your marrow is producing enough new cells.

Common Reasons for Testing

Doctors may order this test if you have symptoms like fatigue, pale skin, or shortness of breath, or if you’re being treated for conditions that affect red blood cell production.

Sample Collection and Preparation

A small blood sample is taken from a vein, usually in your arm. The test requires no special preparation, but fasting may be advised for related blood work.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Reticulocyte Analysis

Frequently asked questions

What does a low or high reticulocyte count mean?
A low reticulocyte count may indicate anemia due to insufficient red blood cell production (e.g., iron deficiency, kidney disease) or blood loss. A high count suggests overproduction, such as from chronic blood loss or certain cancers.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time.
Can I eat or drink before this test?
No special diet is needed, but check with your doctor if you’re also having other blood tests that require fasting.
  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 16, 2026. · Read our editorial policy