Di-8-ANEPPS is a member of the ANEP class of membrane potential dyes. These dyes are weakly fluorescent in aqueous media, and become strongly fluorescent upon binding to lipophilic environments such as membranes. A change in the surrounding electronic field demonstrates a membrane potential-dependent shift in excitation spectra. Di-8-ANEPPS is less susceptible for cellular internalization than other ANEP dyes probably due to a sulfonate group. The response is sufficiently fast to detect transient (millisecond) potential changes in excitable cells, including single neurons, cardiac cells and intact brains. Wavelength Maxima: Excitation 498nm, Emission 713nm Alternative name: 4-[2-[6-(Dioctylamino)-2-naphthalenyl]ethenyl]-1-(3-sulfopropyl)-pyridinium, inner salt. Purity: ≥90% (HPLC). Solubility: Soluble in DMSO. Long Term Storage: -20°C.