Heterobifunctional cross linker enabling the connection of an azide containing compound or biomolecule to one with a thiol. The maleimide group will react preferentially with thiols to form a covalent adduct and the terminal alkyne will react with azides via copper-catalyzed 1,3-dipolar cycloaddition click chemistry. The hydrophilic PEG spacer adds to the water solubility of this reagent, allowing for easy modification cysteine containing biomolecules such as antibodies, proteins and peptides with the terminal alkyne. The PEG spacer also reduces aggregation of modified proteins stored in solution by adding hydrophilic character. A bifunctional linker with sulfhydryl reactive and azide reactive groups. Contains a PEG spacer to increase solubility
