What are Reticulocytes? Reticulocytes are immature red blood cells that still contain remnants of RNA. They spend 1-2 days in the blood before maturing. The reticulocyte count reflects how actively the bone marrow is producing new red blood cells - it's a key test for evaluating anemia and bone marrow response.
Step 1: Supravital Staining Procedure
Mix blood
with stain
with stain
Incubate
15 minutes
15 minutes
Prepare
slide
slide
Ready to
examine
examine
Step 1: Mix blood with stain
Step 2: Incubate 15 minutes
Step 3: Prepare slide
Why New Methylene Blue? This supravital stain (used on living cells) precipitates the ribosomal RNA in reticulocytes, making it visible as a blue-purple reticulum (network) inside the cell. Mature RBCs have no RNA, so they appear uniformly pink/red without any internal network.
📊 Reticulocyte Count Results
Reticulocyte %
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Absolute Count
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Corrected Count
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🔍 Clinical Interpretation
Reference Ranges:
• Reticulocyte %: 0.5-2.0% (of RBCs)
• Absolute count: 25,000-75,000 cells/μL
• Corrected count: Should be >2% in anemia (indicates appropriate marrow response)
Formulas:
• Absolute = (Retic % × RBC count)
• Corrected = (Retic % × Patient Hct) / 45
• Reticulocyte %: 0.5-2.0% (of RBCs)
• Absolute count: 25,000-75,000 cells/μL
• Corrected count: Should be >2% in anemia (indicates appropriate marrow response)
Formulas:
• Absolute = (Retic % × RBC count)
• Corrected = (Retic % × Patient Hct) / 45