FGG, also Known as Fibrinogen gamma chain isoform gamma-A. FGG is the gamma component of fibrinogen, a blood-borne glycoprotein comprised of three pairs of nonidentical polypeptide chains. Following vascular injury, FGG is cleaved by thrombin to form fibrin which is the most abundant component of blood clots. Recombinant human FGG, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.