Invitrogen Alexa Fluor Plus secondary antibodies

A new conjugate technology that provides higher signal to noise ratios for fluorescent imaging and western blotting. Obtain superior images with Alexa Fluor Plus secondary antibodies. Make your low-abundance targets visible, spend less time optimizing, and make every one of your precious samples count. With over 30,000 publications citing their use in research, Alexa Fluor secondary antibodies are the trusted name in fluorescent applications.

Features of Alexa Fluor Plus secondary antibodies

  • Higher signal-to-noise ratio, enabling detection of low-abundance targets
    • Up to 4.2 times higher to signal to noise in immunofluorescence (IF)/ Immunocytochemistry (ICC) imaging
    • Up to 5.8 times higher signal to noise in fluorescent western blotting (WB)
  • Lower cross-reactivity compared to Alexa Fluor secondary antibodies
  • Mix and match our 36 Alexa Fluor Plus secondaries. Choose from 6 colors (2 near-IR) and 6 species combinations for your multi-color imaging and multiplex western blotting workflows.

We have now expanded our menu of Alexa Fluor Plus secondary antibodies, so you can detect with more confidence. Each one of our new Alexa Fluor Plus secondaries was carefully chosen for optimal signal-to-noise performance and degree of labeling using high throughput screening, multiple rounds of validation, and confirmation of performance in multiplex western blotting and multi-color imaging work flows.

Alexa Fluor Plus 488 allows you to see greater detail and shows higher signal-to-noise – secondary  antibody conjugates of Alexa Fluor 488 (left) vs. Alexa Fluor Plus 488 (right). Immunofluorescent analysis of β-III tubulin in E18 Sprague Dawley primary cortical neuronal cells. The cells were fixed with 4% formaldehyde for 15 min, permeabilized with 0.25% Triton™ X-100 detergent in PBS for 10 min, and blocked with 3% BSA in PBS for 30 min at RT. Cells were stained with a β-III tubulin mouse monoclonal antibody (Cat. No. MA1-118) at a dilution of 1:200 in 3% BSA in PBS for 1 hr at RT, and then incubated with either Alexa Fluor 488 goat anti-mouse IgG secondary antibody (Cat. No. A-11029) or Alexa Fluor Plus 488 goat anti-mouse IgG secondary antibody (Cat. No. A32723) at a dilution of 1:1,000 for 1 hr at RT. Nuclei were stained with Hoechst 33342 stain (Cat. No. H3570). The image contains overlay of neuronal tubulin (green) and nuclei (blue). Images were taken on a Zeiss LSM 710 confocal microscope at 40x magnification.

Alexa Fluor Plus 555 enables detection of low abundant targets, showing higher signal-to-noise – secondary antibody conjugates of Alexa Fluor 555 (left) vs. Alexa Fluor Plus 555 (right). Immunofluorescent analysis of β-III tubulin in E18 Sprague Dawley primary cortical neuronal cells. The cells were fixed with 4% formaldehyde for 15 min, permeabilized with 0.25% Triton X-100 detergent in PBS for 10 min, and blocked with 3% BSA in PBS for 30 min at RT. Cells were stained with a β-III tubulin mouse monoclonal antibody (Cat. No. MA1-118) at a dilution of 1:200 in 3% BSA in PBS for 1 hr at RT, and then incubated with either Alexa Fluor 555 goat anti-mouse IgG secondary antibody (Cat. No. A-21424) or Alexa Fluor Plus 555 goat anti-mouse IgG secondary antibody (Cat. No. A32727) at a dilution of 1:1,000 for 1 hr at RT. Nuclei were stained with Hoechst 33342 stain (Cat. No. H3570). The image contains overlay of neuronal tubulin (orange) and nuclei (blue). Images were taken on a Zeiss LSM 710 confocal microscope at 40x magnification.

Alexa Fluor Plus 647 allows you to see a brighter signal over the noise – secondary antibody conjugates of Alexa Fluor 647 (left) vs. Alexa Fluor Plus 647 (right). Immunofluorescent analysis of β-III tubulin in E18 Sprague Dawley primary cortical neuronal cells. The cells were fixed with 4% formaldehyde for 15 min, permeabilized with 0.25% Triton™ X-100 detergent in PBS for 10 min, and blocked with 3% BSA in PBS for 30 min at RT. Cells were stained with a β-III tubulin mouse monoclonal antibody (Cat. No. MA1-118) at a dilution of 1:200 in 3% BSA in PBS for 1 hr at RT, and then incubated with either Alexa Fluor 647 goat anti-mouse IgG secondary antibody (Cat. No. A21235) or Alexa Fluor Plus 647 goat anti-mouse IgG secondary antibody (Cat. No. A32728) at a dilution of 1:1,000 for 1 hr at RT. Nuclei were stained with Hoechst 33342 stain (Cat. No. H3570). The image contains overlay of neuronal tubulin (pink) and nuclei (blue). Images were taken on a Zeiss LSM 710 confocal microscope at 40x magnification.

Alexa Fluor Plus 800 shows more bands at lower dilutions, providing greater sensitivity and range of detection – secondary antibody conjugates of Alexa Fluor Plus 800 goat anti-rabbit (top) vs. competitor (bottom). Western blot analysis of heat shock protein 90 (Hsp90) and histone deacetylase 1 (HDAC1) was performed by loading 3-fold serial dilutions of A431 whole cell lysate (starting at 15 µg) and 2 µL of the Thermo Scientific PageRuler Prestained NIR Protein Ladder (Cat. No. 26635) per well onto a 4-20% Tris-HCl polyacrylamide gel. Proteins were transferred to nitrocellulose membranes (Cat. No. 88018) and blocked with fluorescence blocker for 30 min. Membranes were probed with a Hsp90 polyclonal antibody (Cat. No. PA3-013) at a dilution of 1:5,000 and an HDAC1 polyclonal antibody (Cat. No. PA1-1110) at a dilution of 1:5,000 overnight at 4°C on a rocking platform, washed with TBST, and probed with either Alexa Fluor Plus 800 goat anti-rabbit IgG (Cat. No. A32735) at a dilution of 1:40,000 or another supplier’s goat anti-rabbit 800 IgG conjugate at dilution of 1:15,000 for 45 minutes. Blots were imaged on an infrared fluorescence imaging system.

See real scientists’ reactions to the Alexa Fluor Plus images


Alexa Fluor Plus new packaging

New packaging helps save time and space

  • Storage made easier—the new vials have flagless labels. No more struggling to wrap the flag around the vial to fit it into racks or centrifuges.
  • Identifying made easier—vials have colored caps corresponding to the Alexa Fluor Plus dye of the secondary antibody conjugate. If you are looking for an Alexa Fluor Plus 488 antibody, just look for the green cap.
  • Easier to see how much antibody you have left—vials are clear so you can easily see the volume remaining. No need to pipette from an opaque or solid-colored vial just to estimate how much antibody remains.
  Invitrogen Alexa Fluor Plus Secondary Antibody products
Click on the catalog number below to choose.
Goat anti-Rabbit Goat anti-Mouse Goat anti-Chicken Donkey anti-Goat Donkey anti-Rabbit Donkey anti-Mouse
Alexa Fluor Plus 488 A32731 A32723 A32931 A32814 A32790 A32766
Alexa Fluor Plus 555 A32732 A32727 A32932 A32816 A32794 A32773
Alexa Fluor Plus 594 A32740 A32742 A32759 A32758 A32754 A32744
Alexa Fluor Plus 647 A32733 A32728 A32933 A32849 A32795 A32787
Alexa Fluor Plus 680 A32734 A32729 A32934 A32860 A32802 A32788
Alexa Fluor Plus 800 A32735 A32730 A32935 A32930 A32808 A32789