EZ-Link TFP Ester-PEG12-DBCO is a heterobifunctional cross-linker containing amine-reactive tetrafluoroethylene phenyl (TFP) group and dibenzylcyclooctyne (DBCO) group with a water-soluble long PEG12 spacer between the two groups. This cross-linker can be used to label any primary amine-containing molecule (such as proteins) with long-range DBCO groups. Once a protein or (bio)molecule is labeled with DBCO, it undergoes a copper-free azide-alkyne cycloaddition reaction to form a stable triazole bond with the azide-labeled coupling partner.

EZ-Link TFP Ester-PEG12-DBCO Features include:
•Bioorthogonal—DBCO and azide selectively react to form triazole bonds
•Heterobifunctional—can be combined with amines Reacts with azides
• Solubility—The reagent is readily soluble in water-soluble solvents for dilution into aqueous reaction mixtures
• Stability—TFP esters are more stable to hydrolysis than NHS esters

EZ-Link TFP The ester-PEG12-DBCO can be used to generate different conjugates via bioorthogonal coupling between alkynes and azides (available separately). The coupling or cross-linking method is usually accomplished in two steps. First, protein- or amine-containing molecules are labeled with DBCO groups and excess cross-linker is removed. Second, the azide-containing fraction (prepared independently) was introduced into the same system as the DBCO fraction and labeled under biological conditions without the introduction of any additional reagents, such as copper catalysts.

Classic click reactions involve copper-catalyzed azide-alkyne cycloaddition to label or couple molecules. The disadvantage of this method is that copper ions can impair protein function, damage cells, and reduce the fluorescence of fluorophores. DBCO is unique in that it does not require copper to catalyze the reaction with azide to form the triazole. The eight-membered ring form of the strain allows reaction with azide-modified molecules without a catalyst, thereby preventing copper-induced damage to cells or proteins.