RH 237, also called N-(4-sulfobutyl)-4-(6-(4-(dibutylamino)phenyl)hexatrienyl)pyridinium, is a fast-response potential-sensitive probe. RH 237 is primarily used for imaging membrane potential, synaptic activity, and ion channel activity of neurons. However, the dye is also suitable for imaging the functional activity of mitochondria and heart cells.

Excitation/emission maxima of RH 237 in ethanol are 532/777 nm, respectively. In cell membranes, the spectra of the dye are typically blue-shifted by approximately 20 nm for excitation and 80 nm for emission peaks.

Use 1-5 μM working concentration as a starting point. The exact dye concentration should be defined experimentally.