Invitrogen™ Rhodamine 123, 25 mg

Rhodamine is a generic term for a wide variety of cationic dyes whose fluorescence emission can range from green, orange to red. The table below lists the excitation and emission maxima (nm), as well as molar extinction coefficients (“EC”; cm^-1 M^-1), for various rhodamine dyes (data derived with dye dissolved in methanol).

If you use our FluoVolt Membrane Potential Kit (Cat. No. F10488), the kit provides a background suppressor to reduce this problem. For other indicators, consider the use of BackDrop Background Suppressor (Cat no. R37603, B10511, and B10512).

Molecules that change their structure in response to the surrounding electric field can function as fast-response probes for the detection of transient (millisecond) potential changes. Slow-response dyes function by entering depolarized cells and binding to proteins or membranes. Increased depolarization results in additional dye influx and an increase in fluorescence, while hyperpolarization is indicated by a decrease in fluorescence. Fast-response probes are commonly used to image electrical activity from intact heart tissues or measure membrane potential changes in response to pharmacological stimuli. Slow-responding probes are often used to explore mitochondrial function and cell viability.

A membrane potential indicator selection guide can be found here (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-viability-and-regulation/ion-indicators/membrane-potential-indicators.html).