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Test Code GGT Gamma Glutamyltransferase (GGT) LAB85

Important Note

The following drugs may elevate GGT results: ethanol, phenobarbitone, phenytoin, methaqualone, amyobarbitone, dichloralphenazone, quinalbarbitone and nitrazepam.

Test Method

Enzymatic Rate Method; Beckman DXC600


Testing is performed Monday through Sunday.

Routine orders: Typically completed within 4 hours

Expedite orders: Typically completed within 1 hour after the
specimen arrives at the testing site.

STAT orders: Typically completed within 30 minutes after
the specimen arrives at the testing site.

Useful For

Diagnosis and monitoring of hepatobiliary disease, it is
currently the most sensitive enzymatic indicator of liver

To ascertain whether observed elevations of alkaline phosphatase
are due to skeletal disease (normal GGT) or reflect the presence of
hepatobiliary disease (elevated GGT)

A screening test for occult alcoholism

Specimen Requirement

0.5 mL lithium heparin plasma or serum is required.

CPT Code Information

82977 Chemistry: Glutamylransferase, gamma

Reference Values

7-63 IU/L

LOINC Code Information

2324-2 Gamma Glutamyl Transferase [Enzymatic Activity/Volume] In
Serum Or Plasma

Additional Specimen Collection Information

Collect blood in a lithium heparin, green-top or red-top tube.
PST and SST (gel tubes) are acceptable. Serum or plasma should be
separated from contact with the cells within 2 hours of collection.
Specimens not centrifuged within 4 hours of collection may be
rejected. Refrigerate the specimen if unable to assay within 8
hours of collection. Hemolyzed specimens are not acceptable.
Samples with >3+ lipemia must be cleared prior to analysis. If
sample is stored longer than 48 hours, freeze at -15 to -20 C.
Frozen samples should be thawed only once.