Extralink-Lite PEGDA is a thiol-reactive crosslinker designed for use in HyStem kits. Pack comes with Buffer B for reconstitution. HyStem V2.0 kit components are reconstituted with a buffered 1X PBS. The resulting components will also result in a pH neutral isotonic salt hydrogel. The ending pH, osmo, and rheological properties are the same from Version 1.0 to Version 2.0. Extralink is polyethylene diacrylate (PEGDA) with a molecular weight of 3500 Da. It is a thiol-reactive crosslinker that covalently reacts with the thiol groups in Glycosil, Heprasil and Gelin-S® to form viscoelastic hydrogels. Extralink Lite vials are >80% acrylated and supplied as the crosslinking component in the HyStem kits. Extralink Lite is used to chemically crosslink Glycosil. Extralink Lite is used in place of Extralink for applications where Gelin-S is not included. The higher relative concentration of Glycosil requires less crosslinker to emulate the gelation time and stiffness of HyStem-C and HyStem-HP.