The 3-D Life Dextran-CD Hydrogel SG Kit provides reagents for setting up slow gelling, cell-compatible hydrogels. Its major components are SG-Dextran and the crosslinker CD-Link. When the two reagents are combined, thiol groups on CD-Link form stable thioether bonds with thiol-reactive groups on SG-Dextran, which results in the formation of the gel. The components are mixed at physiological pH (pH 7.2) for optimal cell compatibility. The slow gelation kinetics allows enough time to conveniently manipulate the solution before the onset of gel formation. CD-Link is composed of polyethylene glycol and a matrix metalloprotease (MMP)-cleavable peptide (Pro-Leu-Gly-Leu-Trp-Ala). The MMP-cleavable peptide is designed for a broad range of MMP cleavage including MMPs MMP1, MMP3, MMP7 and MMP9 . It allows cells to spread and migrate within the hydrogel if they express the indicated MMPs. In most cases cell spreading and migration also requires the presence of adhesion peptides. Prior to the crosslinking step, cell adhesion peptides (e.g. 3-D Life RGD Peptide, Cat. No. 09-P-001) can be covalently attached to a portion of the SH-reactive groups on SG-Dextran to provide a cell-adhesive matrix. SG-Dextran hydrogels can be dissolved by the addition of dextranase (3-D Life Dextranase, Cat. No. D10-1), which allows the recovery of chemically fixed or live cells for post-culture analyses (e.g. RT-PCR) or for further cultivation. For instructions, please consult the General Protocol GP-2 "Preparation of 3-D Life Slow Gelling Hydrogels" and the 3-D Life Hydrogels User Guide.