Alexa Fluor® antibody conjugates

High-perfomance fluorescent secondary antibodies for sensitive, multiplex immunodetection

Secondary antibodies conjugated to a fluorescent dye such as Alexa Fluor® can generate a signal which can be detected using a digital imager. The technique is highly sensitive, can be used quantitatively and allows for multiplex detection in a wide range of immunoassay techniques. Typically, they are used in flow cytometry, immunohistochemistry (IHC), and fluorescence microscopy, where fluorophore-conjugated secondary antibodies provide visualization of analytes of interest.

Jackson ImmunoResearch Alexa Fluor^®-conjugated secondary antibodies are conjugated to Donkey and Goat host secondary antibodies that are minimally cross-reactive to many common species to avoid cross-talk between multiple primary antibodies. These conjugates combine highly specific, affinity-purified antibodies with industry-leading fluorophores to deliver exceptional brightness, photostability, and low background noise.

Key features

Alexa Fluor® dyes are among the most widely used fluorophores in life science research due to their superior optical properties.

• Superior brightness & photostability: as a result of intense fluorescence and photobleaching resistance, improving signal longevity during imaging.
• Broad pH stability (pH 4–10): maintains fluorescence across a wide range of experimental conditions.
• Low background & high specificity: cross-adsorbed secondary antibodies minimise species cross-reactivity for cleaner multiplex staining.
• Wide spectral range: available across the visible to near-infrared spectrum for flexible panel design.
• Multiple antibody formats: whole IgG, F(ab')₂, Fab fragments, and Fc-specific Fab (FabuLight™) formats

Available fluorphores

Alexa Fluor® conjugates are available across the visible and near-infrared spectrum, enabling flexible experimental design.

Available formats

Whole IgG Secondary Antibodies

• Full length antibodies (MW~160 kDa) with two antigen binding sites (divalent)
• Suitable for most immunodection workflows
• Cost effective and highly versatile

F(ab')2 Fragment Antibodies

• Reduced Fc region (MW~110 kDa) with two antigen-binding Fab portions linked together by disulfide bond (divalent)
• Suitable for live cell staining and specialist applications
• Reduced background signal and ideal for avoiding Fc receptor interactions

Fab Fragment Antibodies

• Monovalent Fab fragment (MW~50 kDA) for precision applications
• Best for blocking endogenous Ig and double labelling with same-species primaries

FabuLight™ Antibodies

• Fab fragment secondary antibodies (MW~50 kDA) specific to the Fc region of IgG or IgM primary antibodies
• Enable labeling of primary antibodies prior to incubation with cells or tissue
• Time saving alternative to sequential incubation
• Strealined for flow cytometry and Immunohistochemistry applications

Structural formats of antibodies & antibody-derived fragments, including IgG, F(ab′)₂, Fab and FabuLight® antibodies

From left to right:

Materials available for download

Fluorophore selection and panel building blog

Alexa Fluor® fluorescent dyes are a trademark of Life Technologies Corp. They are provided under an agreement between Life Technologies Corp and Jackson ImmunoResearch Laboratories, Inc and the manufacture, use, sale, or import of these dyes is sold pursuant to a license from Life Technologies Corp for use of its fluorescent dye technology. The sale of these dyes or products containing these dyes is expressly conditioned on the buyer not using them (1) in manufacturing; (2) to provide a service, information, or data to an unaffiliated third party for payment; (3) for therapeutic, diagnostic, or prophylactic purposes; (4) to resell, sell, or otherwise transfer this product or its components to any third party, or for any other commercial purpose. For information on purchasing a license to this product for purposes other than research, contact Life Technologies Corp, 5791 Van Allen Way, Carlsbad, CA 92008 or outlicensing@lifetech.com.