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CF®640R Dye

Highly photostable far-red dye

Best photostability among Cy®5-like dyes
Yields conjugates with excellent brightness
Comparible with TIRF and other super-resolution techniques

Figure 1. Normalized absorbance and emission spectra of CF®640R goat anti-mouse conjugate in PBS.

CF®640R is a rhodamine-based far-red fluorescent dye with excitation and emission maxima similar to those of Cy®5 and Alexa Fluor® 647 (Figure 1). CF™640R is much brighter than Cy®5 and at least as bright as Alexa Fluor® 647 (Figure 2). A major advantage of CF®640R over Cy®5 and Alexa Fluor® 647 is its exceptional photostability (Figures 3 and 4). Cy®5 and Alexa Fluor® 647 are cyanine-based dyes and, like other cyanine dyes in general, have intrinsically poor photostability by comparison.

CF®640R is also superior to ATTO 647N, another spectrally similar dye frequently used in single-molecule imaging. As shown in Figure 2, CF®640R yields much brighter antibody conjugates than the ATTO dyes. Due to its high water solubility, CF®640R can label proteins to a high degree of labeling without quenching, unlike the ATTO dyes.

The combination of excellent brightness and photostability makes CF®640R ideal for confocal microscopy, single- molecule imaging and other demanding applications based on fluorescence detection. CF®640R also is compatible with super-resolution imaging by TIRF and FLIMP (learn more about CF® Dyes for Super-Resolution Microscopy).

Figure 2. CF®640R yields brighter antibody conjugates than other far-red dyes. Jurkat cells were stained with mouse anti-CD3 antibody or no primary antibody and goat anti-mouse conjugates of the dyes indicated. Fluorescence was analyzed on a BD FACSCalibur™ flow cytometer in the FL4 channel. Bars represent geometric mean fluorescence.

CF®640R Technical Summary

  • Abs/Em maxima: 642/662 nm
  • Extinction coefficient: 105,000
  • Molecular weight: ~832
  • Excitation laser line: 633, 635 or 640 nm
  • Direct replacement for: Alexa Fluor® 647, ATTO 647N, Cy®5, DyLight® 649

CF®640R Features

  • The best photostability among Cy®5-like dyes
  • Yields highly fluorescent protein conjugates
  • Water-soluble and pH-insensitive
  • Compatible with TIRF and FLIMP super-resolution imaging

Figure 3.  CF®640R is much more photostable than Alexa Fluor® 647. Jurkat cells were stained with mouse anti-CD3 antibody followed by goat anti-mouse secondary antibody conjugates of the indicated dyes. Cells were imaged with continuous mercry arc lamp excitation through a Cy®5 filter cube. Images were captured every 15 seconds for 5 minutes. Fluorescence was normalized to time 0.
Figure 4. Relative photostability of CF®640R and Alexa Fluor® 647 fluorescence. HeLa cells were stained with mouse anti-tublin antibody and goat anti-mouse conjugates of the indicated dyes. Cell were imaged under continuous mercury arc lamp excitement through a Cy®5 filter set. Images were captured at time 0 and after 1 minute and 3 minutes of light exposure.

Figure 5. Section of rat intestine stained with CF®640R phalloidin (actin filaments, magenta) and NucSpot® 470 (nuclei, green).
Figure 6. HeLa cells stained with CellBrite™ Fix 555 (cell surface, red), then methanol-fixed and stained with CF®640R anti-Mitochondrial Marker 113-1 (cyan).
Figure 7. MCF-7 cells stained with CF®640R anti-Cyclin B1 (nuclei/nucleoli, magenta), CF®488A phalloidin (actin filaments, green), and Hoechst (DNA, blue).

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 GE Healthcare.

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Lectins, proteins, nucleotides, toxins, and other probes conjugated to our bright & photostable CF® dyes and other labels.

Primary Antibodies

Growing collection of more than 1000 monoclonal antibodies validated in IHC and other applications. Available with bright and photostable CF® dyes, R-PE, APC, PerCP, HRP, AP, biotin, or purified. Affordable 100 uL trial sizes.

CF® Dye Labeled & Biotinylated Secondary Antibodies

Many host/target species and cross-absorption options, featuring a wide spectrum of our bright & photostable CF® dyes or biotin.

Mix-n-Stain™ Antibody Labeling Kits

Mix-n-Stain™ kits use revolutionary technology that dramatically simplifies antibody labeling and requires no purification. The labeling is covalent and stable. Available with your choice of 24 CF® dyes, biotin, FITC, fluorescent proteins, enzymes, or haptens.

CF® Dye Protein Labeling Kits

Everything you need to label and purify antibodies or other proteins. Choose from 19 bright & photostable CF® dyes or biotin.

Reactive CF® Dyes

Our bright, photostable, highly water soluble CF® dyes with a wide selection of colors and functional groups.

Additional conjugates or reactive dye forms may be added on request, contact to inquire.

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CF® Dyes

See our CF® Dye Quick Reference Table for a list of dyes and summary of their features. Our CF® Dye Selection Guide has more detailed information on each CF® dye, and ordering information for our various CF® dye product lines. You can download CF® dye normalized absorption and emission data in Excel format.

Category: Mix-n-Stain™ Antibody Labeling Kits, CF® Dyes

← FAQs
CF® initially was an abbreviation for Cyanine-based Fluorescent dyes. These were the first patented CF® dyes based on cyanine dye structures. Since then, our CF® dye patent portfolio has expanded to include four different fluorescent dye core structures that cover the fluorescence spectrum from UV to NIR.

Category: CF® Dyes

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The exact chemical structures of CF® dyes are currently confidential but will be fully disclosed at a later stage when pending patents become granted. In general terms, the structure of a CF® dye may be divided into two parts: a) dye core structure (i.e. the aromatic ring skeleton that defines the dye’s color or absorption/emission wavelengths), and b) core structure-modifying elements. At present, CF® dyes bear the core structures of coumarin, pyrene, rhodamine or cyanine dyes. Blue fluorescent CF® dyes are based on coumarin or pyrene dye core structure, while green to near-IR CF® dyes are based on either cyanine or rhodamine dye core structures. Core structure-modifying elements refer to various chemical attachments to the core structure and are a key aspect of the CF® dye invention that makes CF® dyes superior to other commercial dyes.

Category: CF® Dyes

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