**Background**
The measurement of transmembrane voltage ($V_m$) is fundamental to understanding the physiological functions of excitable cells, such as neurons and cardiomyocytes. Changes in membrane potential drive critical biological processes, including the propagation of action potentials and the regulation of ion channel activity. Traditional methods like patch-clamping provide high temporal resolution but are limited in their ability to image spatial voltage distributions across a cell population. Consequently, there is a significant need for high-performance fluorescent probes that can monitor these electrical changes in real-time with high sensitivity. In this context, we will introduce a naphthylstyryl voltage-sensitive dye – Di-8-ANEPPS.
**Definition**
Di-8-ANEPPS is a naphthylstyryl voltage-sensitive dye that shifts both its fluorescence excitation and emission spectra in response to changes in transmembrane voltage. According to the Di-8-ANEPPS description, it is characterized by an excitation maximum of 465 nm and an emission maximum of 635 nm.
**In Vitro Studies**
The Di-8-ANEPPS biological activity has been demonstrated in specialized imaging experiments. In vitro studies utilizing mouse cell staining with Di-8-ANEPPS involved the application of voltage clamp pulses while the cells were immersed in a $\text{Na}^+$-containing solution. The resulting signal, which largely reflects the system voltage, exhibited an asymmetrical positive component upon the application of depolarizing pulses. This phenomenon is interpreted as reflecting a propagating action potential that escapes from the voltage-clamped plasma membrane. Notably, the temporal properties of this signal are similar to those of the “center” signal, with the peak of the signal occurring 0.3 ms after the leading edge of the depolarizing pulse. For researchers seeking detailed Di-8-ANEPPS technical information, these results highlight the dye’s capability for high-resolution confocal imaging of transmembrane voltage. In conclusion, Di-8-ANEPPS is a sensitive fluorescent probe ideal for monitoring rapid electrical changes in cellular membranes.
Keywords
Di-8-ANEPPS, 157134-53-7, Fluorescent Dye, Inhibitor, inhibitor, inhibit
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