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CF®405S Dye

Outshines Alexa Fluor® 405

Brighter conjugates compared to Alexa Fluor® 405
Better match for common instruments
Validated for SIM super-resolution imaging

Figure 1. Normalized spectra of CF®405S goat anti-mouse conjugate in PBS.

CF®405S is a blue fluorescent dye with an absorption peak wavelength matching the 405 nm blue diode laser line (Figure 1). In addition, the emission peak wavelength of the dye is well-centered within the blue detection window of BD flow cytometers. As a result, flow cytometry analysis using CF®405S dye results in much brighter signal than that using Alexa Fluor® 405 (Figure 2). CF®405S also has been validated in super-resolution imaging by SIM. See CF®405S product lines below.

CF®405S Technical Summary

  • Abs/Em maxima: 404/431 nm
  • Extinction coefficient: 33,000
  • Molecular weight: ~1,169
  • Excitation laser line: 405 nm
  • Direct replacement for: Alexa Fluor® 405, Cascade Blue®, DyLight® 405

Figure 2. CF®405S yields brighter conjugates than Alexa Fluor® 405. Flow cytometry analysis in the Pacific Blue® channel of a BD LSRII of Jurkat cells stained with mouse anti-CD3 or isotype control, followed by goat anti-mouse secondary antibody conjugated to Alexa Fluor® 405 or CF®405S with varying numbers of dyes per antibody (degree of labeling, or DOL). Bars represent geometric mean fluorescence.
MCF-7 cells stained with rabbit anti-COXIV, followed by CF®405S goat anti-rabbit (mitochondria, blue) and mouse anti-pPol-II, followed by CF®647 goat anti-mouse (nuclei, red).

CF is a registered trademark of Biotium; Alexa Fluor, Cascade Blue, and DyLight are registered trademarks of Thermo Fisher Scientific.

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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.


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

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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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