EZ-Link Biotin-PEG12-DBCO is a biotinylation reagent that contains a dibenzylcyclooctyne (DBCO) group for copper-free click chemistry attachment to an azide-labeled molecule, enabling the attachment of biotin using a bioorthogonal approach. The DBCO group reacts preferentially with an azide through a copper-free strain-promoted azide-alkyne cycloaddition (SPAAC) reaction to form a stable triazole linkage with an azide-labeled coupling partner. EZ-Link Biotin-PEG12-DBCO contains a 12-unit polyethylene glycol spacer arm for increased water solubility and reach.

EZ-Link Biotin-PEG12-DBCO features include:
• Bioorthogonal—DBCO and azides react selectively to form triazole linkages
• Enhanced solubility—pegylation imparts water solubility to the biotinylated molecule, helping to prevent aggregation of biotinylated antibodies stored in solution
• Irreversible—forms irreversible and stable triazole linkage

Classic click reactions involve a copper-catalyzed azide-alkyne cyclo­addition to label or conjugate molecules. A drawback of this approach is that copper ions can impair protein function, harm cells, and reduce the fluorescence of fluorophores. DBCO is distinct in that it doesn’t require copper to catalyze the reaction with an azide for triazole formation. The strain in the eight-membered ring allows the reaction with azide-modified molecules to occur in the absence of catalysts, preventing copper-induced damage to cells or proteins.