PB dye (Pacific Blue™) 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. The excitation and emission spectrum of PB dye offers minimal overlap with green fluorophore emission spectra, making it an ideal choice for the first violet channel. Conjugates of this dye are strongly fluorescent even at neutral pH.
The amine-reactive PB NHS Etser (Pacific Blue™ succinimidyl ester) can be used to can be used to create blue-fluorescent bioconjugates with excitation/emission maxima ~410/455 nm that are excitable by the 405 nm spectral line of the blue diode (violet) laser. NHS Ester reacts specifically and efficiently with a primary amine (e.g., side chain of lysine residues or aminosilane-coated surfaces) at pH 7-9 to form a stable, covalent amide bond
PB NHS Ester is structurally identical to Pacific Blue™ Succinimidyl Ester sold by ThermoFisher Scientific.