The product is a heat-treated, lyophilized concentrate of coagulation factor XIII, an endogenous enzyme responsible for the crosslinking of fibrin and an essential component of the coagulation cascade. Also known as Fibrin Stabilizing Factor (FSF), Factor XIII is an endogenously produced coagulation factor and the final enzyme within the blood coagulation cascade. Within the body, FXIII circulates as a heterotetramer composed of 2 A-subunits and 2 B-subunits (A2B2). Other products with similar structure and function to the product include Coagulation Factor XIII A-Subunit (Recombinant), which is a recombinant form of the A subunit of human coagulation factor XIII. Compared to the product , which is purified from pooled human plasma, Coagulation Factor XIII A-Subunit (Recombinant) is produced through recombinant DNA technology where the target protein is grown in yeast and then isolated. 9013-56-3 https://www.creativebiomart.net/therapeutic-proteins/p/69/fibrin-stabilizing-factor-fsf/