Serum Cholyglycine (Cholyglycine, CG) is one of the binding cholic acid combined by cholic acid and glycine, within the liver cells, cholesterol transformed into the primary bile acid through the extremely complex enzymatic reaction. Including cholic acid (CA) and chenodeoxycholic acid (CD – CA). there are three hydroxyl (C3, C7, C12) in the steroid nucleus of cholic acid, the hydroxyl at the end of side chains using peptide bonds with glycine, the molecular weight is 462 u.