Filters for Electrochromic Voltage-Sensitive Dyes
Filter Selection Considerations for Electrochromic, Ratiometric Voltage-Sensitive Dyes
In the figure, spectra of the electrochromic, ratiometric voltage-sensitive dye ElectroFluor560 (Di-4-AN(F)EP(F)PTEA) are provided to visualize the best excitation wavelengths and emission filtering for voltage-sensitive dye imaging. Recommended Semrock filter sets, available through AVR-Optics, for all ElectroFluors are available on the product page for ElectroFluor560 as they are on all ElectroFluor product pages.
Absorbance and fluorescence emission spectra are shown with peak wavelengths, optimal excitation wavelengths, and filter edge choices all color coded according to the visible spectrum color bar shown. For single wavelength excitation, the red-edge wavelength is used (see How Electrochromic Voltage-Sensitive Dyes Work) along with long-pass dichroic and emission filters to collect as much emission as possible for signal-to-noise considerations, while eliminating any bleedthrough excitation light. For dual-excitation ratiometric imaging, a blue-edge excitation light source is added by time multiplexing and this wavelength must also be reflected by the dichroic.