N-(m-PEG4)-N'-(DBCO-PEG4)-Cy5 is a Cy5 labeled fluorescent PEG linker containinig DBCO group, which reacts with azide-bearing compounds or biomolecules to form a stable triazole linkage without copper catalyst. DBCO-activated fluorescein dye will be an ideal alternative to copper intolerant applications. The hydrophilic PEG spacer increases solubility in aqueous media. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.