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Test Code GGT Gamma-Glutamyltransferase (GGT)

Additional Codes

Epic: LAB2298

Specimen Required

Specimen Type: Serum

Collection Container/Type

Preferred: Serum gel

Acceptable: Green top (Lithium Heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: 3 mL

Collection Instructions: Centrifuge and separate cells after clot formation and within 1 hour of collection. 

Specimen Minimum Volume

0.25 mL

Specimen Stability

Room temperature: 7 days

Refrigerated: 7 days

Frozen: 1 year

Reference Range


11 - 88 U/L



10 - 70 U/L

Rejection Due To

Unlabeled, mislabeled, wrong tube type, QNS, hemolyzed.

Report Available

Same day

Clinical Significance

Renal tissue has the highest level of GGT, but is elevated in many forms of liver disease. GGT is elevated earlier and is more pronounced in obstructive jaundice and metastatic jaundice. It may reach 5 to 30 times normal levels in intra- or post hepatic biliary obstruction.  GGT is also sensitive to alcohol use.

Method Name

L-gamma-glutamyl-3-carboxy-4-nitroanalide Substrate


Bilirubin and Hemolysis can decrease GGT results by as much as 12-17%.  Intralipid can increase GGT results by as much as 3%.



Day(s) Performed