CF®660C and CF®660R are two spectrally similar fluorescent dyes that emit fluorescence at about 685 nm in the borderline spectral region between far-red and near-IR (Figure 1). Although their absorption maxima are at around 660 nm, both dyes can be sufficiently excited by the 633 or 635 nm laser. When combined with other CF® dyes of shorter wavelengths, CF®660C or CF®660R can serve as a useful long wavelength dye in multi-color detection applications. The two dyes are spectrally similar to Alexa Fluor® 660 but are far superior to the latter in performance.
Like Alexa Fluor® 660, CF®660C is a cyanine-based dye. However, when conjugated to protein, CF®660C is several fold brighter and significantly more photostable than Alexa Fluor® 660 (Figures 2 and 3). CF®660C is also validated in multi-color super-resolution imaging by STORM (learn more about CF® dyes for super-resolution microscopy).
CF®660R is a rhodamine-based dye, and like rhodamine dyes in general, it is exceptionally photostable (Figure 3). CF®660R is also brighter than Alexa Fluor® 660 (Figure 2). The superior photostability and excellent brightness of CF®660R make the dye an ideal choice for confocal microscopy and other demanding applications.
CF®660C Technical Summary
- Abs/Em maxima: 667/685 nm
- Extinction coefficient: 200,000
- Molecular weight: ~3112
- Laser line: 633 or 635 nm
- Direct replacement for: Alexa Fluor® 660, Allophycocyanin (APC)
CF®660R Technical Summary
- Abs/Em maxima: 663/682 nm
- Extinction coefficient: 100,000
- Molecular weight: ~888
- Laser line: 633 or 635 nm
- Direct replacement for: Alexa Fluor® 660, Allophycocyanin (APC)
CF is a registered trademark of Biotium, Inc. Alexa Fluor is a registered trademark of Thermo Fisher Scientific.
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