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Test Code RETA Reticulocytes, Blood

Additional Codes

Ordering Mnemonic



Direct Microscopy or Automated Measurement
Useful for measuring the number of red blood cells delivered by the bone marrow. Reticulocyte count is elevated in active erythropoiesis and decreased in hypoplastic or deficiency conditions.

Performing Laboratory

Holland Hospital Laboratory Services

Specimen Requirements

Container/Tube: Lavender-top (EDTA) tube(s)

Specimen Volume: 4 mL (pediatric: 2 mL) of whole blood

Specimen Transport Temperature


Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

85044-manual (if appropriate)

85045-automated (if appropriate)

Reference Values

≤2 weeks: 2.5-6.5% 

>2 weeks: 0.8-2.1%