Cyanine-Labeling Reagents:  Sulfobenzindocyanine Succinimidyl Esters

Abstract

A synthetic method for shifting the absorption and emission wavelengths of cyanine dye labels by 15-30 nm to the red has been developed. This step significantly increases the potential for preparing fluorescent probes for multiparameter analysis in cytometry and diagnostics. The new sulfobenzindocyanine dyes contain succinimidyl esters as reactive groups and can be readily conjugated to antibodies, avidin, modified DNA, and other amino group-containing materials. The labeling reagents are water soluble, and their fluorescence is not sensitive to pH. One of the reagents, Cy3.205, can be optimally excited with the 568 nm Kr laser line and is useful for confocal microscopy and flow cytometry. Another dye, Cy5.205, can be excited with the 633 He-Ne or 647 nm Kr laser lines available with many flow cytometers and laser-scanning microscopes. New laser diodes emitting near 660-690 nm should also be excellent excitation sources for Cy5.205.

Guanidinium‐Modified Phthalocyanines as High‐Affinity G‐Quadruplex Fluorescent Probes and Transcriptional Regulators

“…[13] The quantum yields of the resulting complexes in water were 0.06 AE 0.02 according to comparisons with both Cy5 and cresyl violet as fluorescent standards. [18] These modest quantum yields are compensated by large molar extinction coefficients for absorbance of Zn-DIGP complexes (e = 30 000-130 000 cm À1 m À1 ; Figure 1 A). Fluorescence data collected using 10 nm Zn-DIGP (Figure 1 B) were analyzed using an independent 2:1 binding model, [9a] and revealed an apparent equilibrium dissociation constant (K d (Figure 1 B).…”

Conformationally Restricted Aza‐Bodipy: A Highly Fluorescent, Stable, Near‐Infrared‐Absorbing Dye

“…Compared to chromophores absorbing in the visible region, problems have been encountered in the design and synthesis of the red-shifted NIR counterparts, such as aggregation, [3] photobleaching, [4] and low fluorescence quantum yields. [4,5] There is a pressing need for the identification of newer, more effective dyes that absorb and emit in the NIR region.…”

Analysis of single‐cell cultures by immunoaffinity capillary electrophoresis with laser‐induced fluorescence detection

“…A simpler approach is the incorporation of laser-induced fluorescence (LIF) detectors using diode lasers (40)(41)(42). The development of the cyanine dyes (Cy3, Cy5), capable of labelling primary amino groups via reactive succinimide ester groups, has greatly enhanced not only labelling efficiency but also signal output (19,(42)(43)(44). These far-red dyes additionally help to reduce the autofluorescence produced by biological tissues and fluids.…”