CHROMOGENIC SUBSTRATE S-2251™ Chromogenix S-2251™ Catalog number: S820332 Description: Chromogenic substrate for plasmin and streptokinase-activated plasminogen. Package: 25 mg Molecular wt: 551.6 Formula: H-D-Val-Leu-Lys-pNA·2HCl View/Download: Insert | Flyer | Brochure