Cy5 aldehyde

Molecular weight: 945.04. Excitation (nm): 651. Emission (nm): 670. Extinction coefficient (cm-1 M-1): 250000. Quantum yield: 0.27. Correction factor (280 nm): 0.03. Cy5 aldehyde is a reactive red fluorescent dye that can react with an amine, hydrazine or hydroxylamine. Aldehyde group is reactive toward amines, hydrazide or hydroxylamine groups from pH 5-9. Unlike amine reactive succinimidyl ester group (NHS), aldehyde can react with N-terminal amine groups at acidic pH, a condition sometimes required for certain bioconjugation reactions. Aldehyde reacts with amine group to form an intermediate Schiff bond. Further reduction with hydride will form a stable C-N bond. Reaction between aldehyde and other groups allows site-specific conjugation and labeling of fluorescein dyes to desired position on targeted molecules. Conjugated Cy5 dye can be easily detected by a common fluorescence instrument under Cy5 channel.