Far-red fluorescent dyes offer the advantage of ultra sensitive detection because background signal due to autofluorescence in most biological samples is minimal in this spectral region. For many years, the cyanine dye Cy®5 has been the dye of choice for such detection. More recently, Alexa Fluor® 647 has been developed as a better alternative by having brighter fluorescence and higher photostability. Despite the improvement, Alexa Fluor® 647 still lacks sufficient photostability required for many demanding applications. On the other hand, while Alexa Fluor® 633 is photostable, its fluorescence on proteins is very weak.
Using new chemistry, scientists at Biotium have successfully developed CF®633 to overcome the limitations of other far-red dyes. CF®633 is significantly brighter than spectrally similar dyes (Figure 2). The most important advantage of CF®633, however, is its unmatched photostability (Figure 3). The combination of superior brightness and photostability make CF®633 the best choice for any detection system using a 633 or 635 nm laser excitation source. CF®633 also is compatible with TIRF and other super-resolution imaging methods (learn more about CF® Dyes for Super-Resolution Imaging).
CF®633 Technical Summary
- Abs/Em maxima: 630/650 nm
- Extinction coefficient: 100,000
- Molecular weight: ~820
- Laser line: 633 or 635 nm
- Alternative for: Alexa Fluor® 633, Alexa Fluor® 647, Cy®5 and DyLight® 649
- Fluorescence lifetime:
τ (ns)/free acid in PBS pH 7.4, ε (ns) = 3.39* (in water)
τ (ns) /S.Ab§ = 3
Lifetime data obtained via customer communication under different experimental conditions and imaging setup.
Visit our FAQ for more fluorescence life time information on CF® dyes.
CF®633 Features
- Brightest far-red fluorescent conjugates
- Excellent photostability
- Highly water soluble and pH-insensitive
- Compatible with TIRF and other super-resolution methods
CF is a registered trademark of Biotium Inc. Alexa Fluor and DyLight are registered trademarks of Thermo Fisher Scientific; Cy Dye is a registered trademark of Cytiva.