Alexa Fluor Secondary Antibodies

Invitrogen Alexa Fluor protein and antibody conjugates produce fluorescence outputs that exceed those of other spectrally similar fluorophore conjugates and do not photobleach as easily as classic fluorescent secondary antibodies. With more than 80,000 publications, our Alexa Fluor secondary antibodies are reliable research tools. Browse our comprehensive portfolio of Alexa Fluor and Alexa Fluor Plus secondary antibodies for fluorescent detection of primary antibodies in a wide range of applications, such as cell imaging, flow cytometry, and western blotting.

See all Alexa Fluor secondary antibodies See Alexa Fluor Plus secondary antibodies

Alexa Fluor secondary antibody product information

Alexa Fluor secondary antibodies have been tested extensively to help ensure optimal performance. Alexa Fluor Plus secondary antibodies have been optimized further to enable better detection of low-abundance targets and are excellent for use in rare or precious samples.

	Alexa Fluor Secondary Antibodies	Alexa Fluor Plus Secondary Antibodies
Use	Designed for use in a variety of cell analysis and protein analysis applications to detect targets at varying expression levels	Designed to help detect and visualize low-abundance targets in rare or precious samples Optimized for excellent multiplexing experiments
Applications	Immunohistochemistry Immunocytochemistry Immunofluorescence Western blot	Multiplex immunocytochemistry Multiplex immunohistochemistry Multiplex western blot
Key product attributes	Improved brightness, pH insensitivity, and photostability compared to classic dyes Broad spectral range coverage	Higher signal-to-noise ratio than traditional Alexa Fluor secondary antibodies Up to 4.2x higher signal to noise in immunohistochemistry/immunocytochemistry Up to 5.8x higher signal to noise in fluorescent western blot Lower cross-reactivity compared to traditional Alexa Fluor secondary antibodies
Targets species available	Mouse Rabbit Goat Rat Human Hamster Chicken Sheep Guinea pig	Mouse Rabbit Goat Rat Human Chicken
Fluorophores available	18 Alexa Fluor dyes available	7 Alexa Fluor Plus dyes available
Antibody formats available	Whole IgG F(ab’)2 Fragment F(ab) Fragment VHH	Whole IgG F(ab’)2 Fragment
Mountant compatibility	Most standard fixatives. See the selection guide: Mounting Media and Antifades Recommended: ProLong Antifade Mountants for Fixed Cells ProLong Antifade Reagents for Live Cells

Alexa Fluor and Alexa Fluor Plus selection guide

Alexa Fluor conjugate (click for dye information)	Excitation/emission (in nm)	See available secondary antibodies
Alexa Fluor 350 Dye	343/441	Alexa Fluor 350 secondary antibodies
Alexa Fluor 405 Dye	401/422	Alexa Fluor 405 secondary antibodies
Alexa Fluor Plus 405 Dye	404/455	Alexa Fluor Plus 405 secondary antibodies
Alexa Fluor 430 Dye	431/540	Alexa Fluor 430 secondary antibodies
Alexa Fluor 488 Dye	499/520	Alexa Fluor 488 secondary antibodies
Alexa Fluor Plus 488 Dye	493/518	Alexa Fluor Plus 488 secondary antibodies
Alexa Fluor 514 Dye	518/543	Alexa Fluor 514 secondary antibodies
Alexa Fluor 532 Dye	534/553	Alexa Fluor 532 secondary antibodies
Alexa Fluor 546 Dye	561/572	Alexa Fluor 546 secondary antibodies
Alexa Fluor 555 Dye	553/568	Alexa Fluor 555 secondary antibodies
Alexa Fluor Plus 555 Dye	558/572	Alexa Fluor Plus 555 secondary antibodies
Alexa Fluor 568 Dye	579/603	Alexa Fluor 568 secondary antibodies
Alexa Fluor 594 Dye	590/618	Alexa Fluor 594 secondary antibodies
Alexa Fluor Plus 594 Dye	590/618	Alexa Fluor Plus 594 secondary antibodies
Alexa Fluor 633 Dye	631/650	Alexa Fluor 633 secondary antibodies
Alexa Fluor 635 Dye	633/648	Alexa Fluor 635 secondary antibodies
Alexa Fluor 647 Dye	650/671	Alexa Fluor 647 secondary antibodies
Alexa Fluor Plus 647 Dye	658/675	Alexa Fluor Plus 647 secondary antibodies
Alexa Fluor 660 Dye	663/691	Alexa Fluor 660 secondary antibodies
Alexa Fluor 680 Dye	681/704	Alexa Fluor 680 secondary antibodies
Alexa Fluor Plus 680 Dye	687/704	Alexa Fluor Plus 680 secondary antibodies
Alexa Fluor 700 Dye	696/719	Alexa Fluor 700 secondary antibodies
Alexa Fluor 750 Dye	752/776	Alexa Fluor 750 secondary antibodies
Alexa Fluor Plus 800 Dye	789/794	Alexa Fluor Plus 800 secondary antibodies

Alexa Fluor secondary antibody formats

Our Alexa Fluor and Alexa Fluor Plus conjugated secondary antibodies are now available in a variety of formats, each offering unique benefits.

F(ab) and F(ab’)2 fragment Alexa Fluor secondary antibodies

We offer F(ab) and F(ab’)2 fragment secondary antibodies with various Alexa Fluor conjugate options. These secondary antibody fragments are cross-adsorbed to increase sensitivity, reduce background staining, and offer several benefits over whole IgG antibodies. Because of their smaller size they can more easily penetrate complex tissue models compared to whole IgG molecules, potentially leading to more antigen binding capability. This property, combined with Alexa Fluor and Alexa Fluor Plus conjugation, makes these molecules valuable staining tools in immunohistochemistry and immunofluorescent experiments.

Fluorescent image of human small intestine

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Comparison of whole IgG with F(ab’)2 Alexa Fluor Plus 555 secondary antibody in human small intestine (duodenum). (A) Cell junctions were stained using Cadherin-17 Monoclonal Antibody (3B10A9) (Cat No. 60351-1-IG) and Alexa Fluor Plus 555 whole IgG secondary antibody. (B) Under matched conditions, cell junctions were stained using the same primary antibody against Cadherin 17 and F(ab')2-Goat anti-Mouse IgG (H+L) Cross-Adsorbed Secondary Antibody, Alexa Fluor Plus 555 (Cat. No. A48287). Nuclei were stained with Hoechst 33342 (Cat. No. H3570). Images were captured on an EVOS M7000 instrument at 4x magnification.

Explore: F(ab) and F(ab’)2 Fragment Secondary Antibodies

Superclonal recombinant Alexa Fluor secondary antibodies

Superclonal recombinant secondary antibodies provide polyclonal sensitivity with monoclonal specificity in a recombinant format. Now available with a variety of Alexa Fluor and Alexa Fluor Plus conjugates, our Superclonal recombinant secondary antibodies help ensure reliable results with their lot-to-lot consistency.

Fluorescent image of HeLa cells and bar chart showing consistency between lots

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Superclonal secondary antibodies are designed to provide lot-to-lot consistency. Endogenous TOMM20 in HeLa cells were labeled with rabbit TOMM20 monoclonal primary antibody, which was then detected with four different lots of Goat anti-Rabbit IgG (Heavy Chain), Superclonal Recombinant Secondary Antibody, Alexa Fluor Plus 488 (Cat. No. A55053) (green). Comparable signal and noise fluorescence intensities from these four lots demonstrate lot-to-lot consistency of Superclonal secondary antibodies. Inset represents control cells with no primary (NP) antibody to assess noise.

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Alexa Fluor ReadyProbes Secondary Antibodies

ReadyProbes secondary antibodies are conjugated with bright and photostable Alexa Fluor 488 and Alexa Fluor 594 dyes to offer convenient and robust labeling. These Alexa Fluor secondary antibodies recognize IgG heavy chains and all classes of immunoglobulin light chains from either mouse or rabbit. Like other ReadyProbes reagents, these secondary antibodies are provided in a convenient dropper bottle format. No pipetting or dilutions are required.

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Rabbit IgG (H+L) Cross-Adsorbed Secondary Antibody in ICC/IF. CAKI cells were plated on coverslips overnight. Then, cells were fixed and permeabilized. Following suppression of background binding using Image-iT FX Signal enhancer (Cat. No. R37107), peroxisomes were labeled using a rabbit anti-PMP70 antibody followed by detection with Goat anti-Rabbit IgG (H+L) Cross-Adsorbed ReadyProbes Secondary Antibody, Alexa Fluor 488 (Cat. No. R37116). Cells were washed three times in dPBS and nuclei were stained with NucBlue Fixed Cell ReadyProbes Reagent (DAPI) (Cat. No. R37606) and actin was visualized with ActinRed 555 ReadyProbes Reagent (Rhodamine phalloidin) (Cat. No. R37112). Images were acquired on the EVOS FL Auto imaging system using a 40x coverslip-corrected objective.

Explore: ReadyProbes Ready-to-Use Imaging Reagents