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Test Code LAB85 Gamma Glutamyltranspeptidase (GGT), Blood

Performing Laboratory

St. Louis Children's Hospital Laboratory - Chemistry

Specimen Requirements

Patient Preparation: None

Collection Container/Tube:

Preferred: Mint green-top lithium heparin (MNTGRN LiHep) tube

Acceptable: Green samplette/microtainer, plain red-top tube, Gold SST gel tube, or lavender-top (EDTA) tube

Submission Container/Tube: If specimen is coming from outside facility and collected in a microtainer, plain red-top tube, or lavender-top tube aliquot processed sample into a plastic vial for transport (labeling with specimen type).

Specimen Collection Volume: 1.0 mL (minimum 0.6 mL)

Special Instructions: None

 

Sample Rejection

Mislabled or unlabeled specimens

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 2 hours from receipt in performing lab

Reference Values

Reference Interval: 

<3 months: 20-200 Units/L                                                             
3 months - 1 year: 5-115 Units/L
1-12 years: 5-35 Units/L
≥ 12 years:  
     Female: 5-35 Units/L
     Males: 10-50 Units/L

Critical Value: >600 Units/L (all ages)

Critical test results will be called back automatically initially and every 168 hours thereafter.

 

Methodology

Enzymatic Colorimetric

Limitations

  • In very rare cases gammopathy, in particular type IgM (Waldenstrom's macroglobulinemia) may cause unreliable results.

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processg Instructions: Centrifuge to separate. If specimen is collected in microtainer, plain red-top tube, or lavender-top tube aliquot sample into a Roche false-bottom tube for testing (labeling aliquot with specimen type).

Processed Volume: 0.3 mL plasma/serum

Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 8 hours
Plasma/Serum (processed) Refrigerated (preferred) 7 days
  Ambient  7 days
  Frozen  2 months     

Test Classification and CPT Code

82977

LOINC

2324-2

Last Reviewed

06/2025