Pacific Blue™ dye

Pacific Blue™ dye is a bright blue-fluorescent dye optimally excited by the 405 nm line of the violet laser and with excitation/emission at 410/455 nm. Conjugates of this dye are strongly fluorescent even at neutral pH.

Pacific Blue™, Pacific Green™ and Pacific Orange™ dye conjugates can be simultaneously excited at 405 nm and emit at 455 nm, 500 nm and 551 nm, respectively, facilitating three-color analysis.

We offer Pacific Blue™ dye conjugated to a variety of antibodies, peptides, proteins, tracers, and amplification substrates optimized for cellular labeling and detection. In addition, reactive dyes and protein labeling kits are available so that you can produce your own antibody conjugates or probes.

Pacific Blue™ dye dashboard

Initial brightness



The violet laser–excitable Pacific Blue® dye is optimized for use in flow cytometry applications, but can also be used for high-abundance targets in fluorescence microscopy.


Photostability in buffer


Pacific Blue™ dye products

We offer a broad range of Pacific Blue™ dye products including labeling kits, labeled antibodies, bioconjugates, and more.

Pacific Blue™ dye

Fluorescence excitation and emission spectra of Pacific Blue™ dye.

Pacific Blue™ reactive dyes

Select dye-labeling chemistries for conjugation with the following reactive groups: 

Amine Thiol

Pacific Blue™ dye protein/antibody labeling kits

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

Target protein Kit Cat. No.
Site-specific antibody labeling
<1–20 µg mouse IgG1 Zenon® Pacific Blue™ Mouse IgG1 Labeling Kit Z25041
<1–20 µg mouse IgG2a Zenon® Pacific Blue™ Mouse IgG2a Labeling Kit Z25156
Conventional antibody/protein labeling
10–20 µg antibody APEX™ Pacific Blue™ Antibody Labeling Kit A10478
100 µg antibody/protein Pacific Blue™ Antibody/Protein Labeling Kit P30013
1 mg antibody/protein Pacific Blue™ Antibody/Protein Labeling Kit P30012

Violet laser–compatible antibody conjugates

We offer Pacific Blue™, Pacific Green™ and Pacific Orange™ dyes as well as Qdot® probes for use with the violet laser. In addition to primary and secondary antibody conjugates of these dyes, we’ve developed kits for cell proliferation, immunophenotyping, dead cell discrimination, apoptosis, and cell cycle analysis—all aimed at helping you maximize the data you can get from your violet laser–equipped flow cytometer.

Pacific Green dye conjugates  


Excitation spectra (dotted lines) and emission spectra (solid lines) for Molecular Probes® violet laser–excited Pacific Blue™ dye (blue), Pacific Green™ dye (green), and Pacific Orange™ dye (orange). The shaded area represents the emission bandpass filter (522/31) used for detection of the Pacific Green™ dye.


Molecular Probes® Handbook

Molecular Probes HandbookThe significantly revised 11th Edition is the most complete fluorescence labeling and detection reference available. The Molecular Probes® Handbook can help you achieve the best experimental results for your fluorescence labeling and detection experiments. View the handbook online or order your own copy.


Flow cytometry instrument controls and standards

Flow instrument controlsKeep your flow cytometry running at peak efficiency with Molecular Probes® instrument set-up, calibration, and counting beads including alignment and linearity beads, compensation tools, and cell-counting beads.


Cell stain tool

Cell stain toolStain your own cell by using our simulation tool to develop reproducible results with many of our signature fluorescent dyes. Develop your multiplexing strategy for antibody probes, reactive dyes, and counterstains to create your perfectly labeled fluorescent cell.


Fluorescence SpectraViewer

Fluorescence SpectraviewerPlot and compare spectra and check the spectral compatibility for common fluorophores including all the Molecular Probes® fluorescent probes. The Fluorescence SpectraViewer tool is formatted for both microscope imaging and flow cytometry applications.