The product, also known as catridecacog, is a recombinant form of the Factor XIII-A2 homodimer composed of two factor XIII (FXIII) A-subunits. Also known as Fibrin Stabilizing Factor (FSF), Factor XIII is an endogenously available coagulation factor and the final enzyme within the blood coagulation cascade. Within the body, FXIII circulates as a heterotetramer composed of 2 catalytic A-subunits and 2 non-catalytic B-subunits (FXIII-A2B2). When activated by thrombin at the site of injury, the FXIII A2B2 pro-enzyme is cleaved resulting in activation of the catalytic A-subunit and dissociation from its carrier B-subunit. When supplied as the recombinant form, the product binds to free human FXIII B-subunit resulting in a heterotetramer (rA2B2) with a similar activity profile and half-life as the endogenously available form. The product is manufactured as an intracellular, soluble protein in yeast (Saccharomyces cerevisiae) production strain containing the episomal expression vector, pD16. It is subsequently isolated by homogenization of cells and purification by several chromatography steps, including hydrophobic interaction and ion exchange chromatography.