Di-(N-succinimidyl) glutarate is an amine-reactive homobifunctional cross-linker. At neutral or slightly basic pH (7-9), it rapidly attacks solvent accessible lysine-NH*2* groups and N-termini. It represents the shortest of the 3 most used neutral N-crosslinkers (DSG, DSS, DSSeb). DSG crosslinking takes place through amine-reactive NHS esters at both ends of a 5-atom (7.7 angstrom) spacer arm. DSG must be dissolved in an organic solvent, such as DMSO or DMF, then added to an aqueous crosslinking reaction.