Description
Introduction: Gamma-glutamyl transferase (GGT or GGTP, or Gamma-GT) is involved in the transfer of amino acids across the cellular membrane. It is also involved in glutathione metabolism by transferring the glutamyl moiety to a variety of acceptor molecules including water, certain L-amino acids and peptides. Leaving the cysteine product to preserve intracellular homeostasis of oxidative stress. GGT is found on the cell surface on all cells, with particularly high concentrations in the liver, bile ducts, and kidney. The enzyme is also present in other tissues, such as the epididymis. Elevated GGT is a marker of recent alcohol misuse. It may indicate excess alcohol consumption up to 3 or 4 weeks prior to the test. It is also used as a diagnostic marker for other types of liver damage or conditions attributable to other causes unrelated to alcohol abuse.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to GGT. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for GGT and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain GGT, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of GGT in the samples is then determined by comparing the O.D. of the samples to the standard curve