Spectrally similar to Cy7™ dye, HiLyte Fluor™ 750 dye is the longest-wavelength HiLyte Fluor™ dye currently available. Its fluorescence emission maximum at 778 nm is well separated from commonly used far-red fluorophores, including HiLyte Fluor™ 647, HiLyte Fluor™ 680 or allophycocyanin (APC), facilitating multicolor analysis. Extinction coefficient is 275,000 M^-1cm^-1, with a quantum yield of 0.12. With a peak excitation at ~753 nm, conjugates of HiLyte Fluor™ 750 dyes can be excited by a xenon-arc lamp or dye-pumped lasers operating in the 720–750 nm range. Its near infrared spectra render the HiLyte Fluor™ 750 dye the ideal candidate for in vitro and in vivo tissue imaging.

Figure 1. Absorption and emission spectra of HiLyte Fluor™ 750.

Figure 2. In-vivo image of a rat injected with 20 nmol of c[RGDyK(HiLyte Fluor™ 750)] peptide-dye conjugate 3h post injection (image courtesy of J. Rey, Univ. of South Florida).

Figure 3. Western blot analysis of zebrafish lysate (5 dpf) with Z-Fish™ anti-p53 (CT), cat# 55342. An imunoreactive band at ~53 kDa was detected (A); this band was blocked by the immunizing peptide (B). HiLyte Fluor™ 750 –conjugated secondary antibody, cat# 28176-H750 was used and signals detected with an infrared-imaging system (Odyssey, Li-Cor, Inc).

Table 1. HiLyte Fluor™ 750 is available in various reactive forms.

Table 2. HiLyte Fluor™ 750 labeled secondary antibodies.

Table 2. AnaTag™ HiLyte Fluor™ 750 protein (IgG) labeling kits.