Alexa Fluor® 405Invitrogen Alexa Fluor 405 dye is a blue-fluorescent dye with excitation ideally suited for the 407 nm spectral line of the krypton laser or the 408 nm violet laser diode. Alexa Fluor 405 dye is pH-insensitive over a wide molar range, helping ensure that you get stable signals in live-cell imaging applications.

Alexa Fluor 405 conjugates exhibit an excitation maximum at 401 nm and emission maximum at 421 nm. It is particularly useful in multicolor applications, including flow cytometry and super-resolution microscopy using STORM.

For imaging low-abundance targets, such as neuronal tracing in fine outgrowths, an anti–Alexa Fluor 405 antibody is available for signal amplification. Using this anti-dye antibody in conjunction with standard enzyme-mediated immunohistochemical methods can allow you to generate a more permanent, fade-free signal for light microscopy.

We offer Alexa Fluor 405 dye conjugated to a variety of antibodies and peptides optimized for cellular labeling and detection. In addition, reactive dye forms and protein labeling kits are available to enable you to generate your own antibody conjugates or probes.

Alexa Fluor 405 dye dashboard

Initial brightness

Alexa Fluor 405 dye provides versatility in the blue channel for imaging and is compatible with the violet laser for flow cytometry. It is extremely useful in stochastic optical reconstruction microscopy (STORM) where it is used as an activator. It is also used to label conjugates for SIM. 

Photostability in buffer


Photostability in antifade


Performance in SRM


Alexa Fluore® 405 fluorescence

Alexa Fluor 405 conjugated to CD4, used to label 10,000 cells and optimized for signal-to-background ratio.


Alexa Fluor 405 reactive dyes

AmineAldehyde, ketone, carboxylate, or phosphate

Alexa Fluor 405 protein/antibody labeling kits

Select an optimized labeling kit for your target antibody or protein:

Target proteinKitCat. No.
Site-specific antibody labeling
<1–20 µg mouse IgG1Zenon Alexa Fluor 405 Mouse IgG1 Labeling KitZ25013
<1–20 µg mouse IgG2aZenon Alexa Fluor 405 Mouse IgG2a Labeling KitZ25113
<1–20 µg mouse IgG2bZenon Alexa Fluor 405 Mouse IgG2b Labeling KitZ25213
<1–20 µg rabbit IgGZenon Alexa Fluor 405 Rabbit IgG Labeling KitZ25313
Alexa Fluor Dye stained cell

Alexa Fluor dye family

Alexa Fluor dyes are among the most trusted fluorescent dyes available today. Learn more about the:

Not for resale. Super Bright Polymer Dyes are sold under license from Becton, Dickinson and Company.

Brilliant Ultra Violet™ and Brilliant Violet™ are trademarks or registered trademarks of Becton, Dickinson and Company or its affiliates, and is used under license.

For Research Use Only. Not for use in diagnostic procedures.