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Test Code LAB296 Reticulocyte Count, Blood

Performing Laboratory

St. Louis Children's Hospital - Hematology

Specimen Requirements

Patient Preparation: None

Container/Tube  
Preferred: Lavender-top (EDTA) tube
Acceptable: Lavender-top (EDTA) samplette/microtainer
Collection Volume: 

Vacutainer: 2.0 mL (minimum 0.5 mL)
Microtainer: minimum 0.3 mL

Submission Container/Tube: If specimen is coming from outside facility, send whole blood in original collection container.
Special Instructions: Immediately invert tube gently 8-10 times after collection to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting). Do not overfill tube. Send to lab promptly. 

Sample Rejection

Mislabeled or unlabeled specimens

Clotted specimens

Logistics

Test Availability: Monday-Sunday
Cut-off time: None; performed as received
Turnaround Time: Same day; 1 hour from receipt in performing lab

Reference Values

Reference Interval:

Retic Pct
   <3 days: 1.5-6.05 %                                                          
   > o r= 3 days: 0.4-2.9 %
Retic Abs  
   <3 days: 60-300 k/cumm
   ≥ 3 days: 20-87 k/cumm                                                    
Reticulocyte Hemoglobin
   <18 years: 28.5-38.0 pg
   ≥ 18 years: 30.5-38.0 pg                                                            

Critical Value: None established

Methodology

Flow Cytometry

Limitations

  • NA

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: DO NOT SPIN. Give specimen directly to Hematology bench
Processed Volume: NA
Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 24 hours
  Refrigerated     24 hours
  Frozen  unacceptable       

NOTE: refrigerated specimens must be warmed to room temperature before analysis. 

Test Classification and CPT Code

85045

LOINC

retic pct: 17849-1

retic abs: 60474-4

Last Reviewed

07/2025