5.8. Determination of Mitochondrial Membrane Potential by Rh123

Rhodamine (Rh) 123 is a powerful probe for monitoring the abundance and activity of mitochondria.^71,72 To conduct the assay, Rh123 at a final concentration of 20 μM was added to the cells in a 12-well plate for 15 min. The reaction mixture was removed and the cells were washed with HBSS three times carefully so that the cells are not washed off. Imaging was conducted using a blue filter in a microscope (Leica DMi8, Wetzlar, Germany). The resultant green fluorescence intensity is directly proportional to the MMP; higher the green Rh123 fluorescence, greater the MMP and vice-versa.