Cy5.5 Maleimide (also sold under as sulfo-Cyanine5.5 Maleimide) is a bright and photostable near-IR dye that is spectrally similar to Alexa Fluor® 680, DyLight 680™, and IRDye® 680 dye. Cy5.5 Maleimide is completely water-soluble and often a reagent of choice for labeling antibodies, peptides, and proteins that are sensitive toward organic co-solvents. Cy5.5 conjugates are pH insensitive from pH 4 to pH 10 and produces minimal autofluorescence of biological specimens in this region of the spectrum. Fluorescence of this long-wavelength Cyanine dye is not visible to the human eye but is readily detected by most imaging systems.
Maleimide is the most popular sulfhydryl-reactive reactive group for conjugating the dye to a thiol group on a protein, oligonucleotide thiophosphate, or low molecular weight ligand. The maleimide group specifically and efficiently reacts with reduced thiols (sulfhydryl groups, –SH) at pH 6.5 to 7.5 to form stable thioether bonds.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.
