* Gamma Glutamyl Transferase Mnemonic GGT Synonym Gamma GT - GGT Specimen Collection Requirements Collect Serum or Plasma, one 5.0 mL gold (SST), 7.0 mL red, or 3.0 mL mint green (lithium heparin, PST) top tube Handling Allow serum to clot completely at room temperature (minimum for SST: 30 minutes; minimum for red top tubes: 60 minutes). Centrifuge and separate serum or plasma from cells within 2 hours of collection. Preferred Volume 1.0 mL Serum/Plasma Minimum Volume 0.25 mL Serum/Plasma (0.6 mL minimum whole blood draw) Transport Refrigerated (2-8°C) Rejection Criteria Grossly hemolyzed specimen Stability AFTER SEPARATION FROM CELLS: Room Temperature (18-26°C): 24 hours; Refrigerated (2-8°C): 7 days; Frozen (≤ -20°C): 1 month Testing Information Performed 7 days/week Reported 24 hours Method Enzymatic Reference Values Reference Values For age related ranges see Chemistry Age Related Reference Ranges and Critical Values. Comments Legacy Laboratory Services has validated the use of lithium heparin plasma with this assay. Lithium heparin plasma has not been approved or cleared by the U.S. Food and Drug Administration (FDA) for use with this test. Legacy is authorized under Clinical Laboratory Improvement Amendments (CLIA) to perform high-complexity testing. CPT Codes 82977 Last Updated: Saturday, January 30, 2021 01:37:21 AM Client Services: 503-413-1234