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Test Code LAB322 Erythrocyte Sedimentation Rate (ESR)

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

Specimens that are greater than 8 hours old kept at room temperature or 12 hours old that have been refrigerated

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:

<1 day: <2 mm/hr
1 day -18 years: 3-13 mm/hr
FEMALES:  
   18-50 years: 1-20 mm/hr
   ≥ 50 years: 1-30 mm/hr
MALES:  
   18-50 years: 1-15 mm/hr
   ≥ 50 years: 1-20 mm/hr                                                     

Critical Value: none established

Methodology

ESR Stat6 Plus (centrifugation and laser optic principle)

Limitations

  • Specimens with hemoglobin levels <or=5.0 g/dL are not compatible with ESR Stat6 and will display error message
  • Certain drugs may cause falsely elevated or falsely decreased results. Call lab at 314-454-4268 for list of drugs if result is in question.

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: DO NOT SPIN. Give specimen directly to Hematology bench
Processed Volume: minimum 0.3 mL whole blood
Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 8 hours
  Refrigerated     12 hours
  Frozen  unacceptable       

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

Test Classification and CPT Code

85652

LOINC

30341-2

Last Reviewed

07/2025