Free Cyanine3 carboxylic acid (Cy3® carboxylic acid analog), non-activated dye. Non-sulfonated reagent, with good solubility in organic solvents, and limited aquous solubility. The dye can be used as a non-reactive fluorophore, for control experiments, and for calibration.
For coupling with amines, and labeling, consider using Cyanine3 NHS ester, or water-soluble sulfo-Cyanine3 NHS ester.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.