Cyanine5 maleimide is a mono-reactive dye which selectively couples with thiol groups (for example, with cysteines in peptides and proteins) to give labeled conjugates.
Cyanine5 is an analog of Cy5®, a common fluorophore which is compatible with various instrumentation like microscopes, imagers, and fluorescence readers.
For the labeling of antibodies and sensitive proteins we recommend to use the water soluble sulfo-Cyanine5 maleimide.