HiLyte™ Fluor 750-streptavidin conjugate has been optimized in fluorophore/protein labeling ratio to ensure high fluorescent signal and uncompromised streptavidin function. Spectrally similar to Cy®7 dye, HiLyte™ Fluor 750 is the longest-wavelength HiLyte™ Fluordye currently available. Its fluorescence emission maximum at 778 nm is well separated from commonly used far-red fluorophores such as HiLyte™ Fluor 647 or allophycocyanin (APC), facilitating multicolor analysis. With a peak excitation at ~754 nm, conjugates of HiLyte™ Fluor 750 dyes are well excited by a xenon-arc lamp or dye-pumped lasers operating in the 720–750 nm range. The fluorescence signal of HiLyte™ Fluor 750-conjugate can be observed at 778 nm with the excitation at 754 nm.