Sulfo-Cy5 dye is a water-soluble, bright far-red fluorescent dye, one of the most popular far-red fluorescent dyes, with excitation light well suited for 633 nm or 647 nm laser lines. It is often the reagent of choice for protein and peptide labeling, and Sulfo-Cy5 conjugates of antibodies, peptides and proteins are pH insensitive in the pH 4 to pH 10 range. A significant advantage of using long wavelength dyes such as Cy5 or AF 647 dyes compared to other fluorophores is the low autofluorescence of biological samples in this region. spectrum. The carboxylic acid of Sulfo Cy5 dyes is the reagent of choice for the preparation of custom reactive esters, which are often not commercially available. Examples of such activated esters include sulfo-NHS, TFP (2,3,5,6-tetrafluorophenol), STP (4-sulfo-2,3,5,6-tetrafluorophenol, sodium salt). Another common application of non-activated carboxylic acids is peptide modification during solid-phase synthesis, which often requires in situ activation using peptide coupling reagents such as HATU. Cy5 Acid is also frequently used for control experiments and calibration.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.
