Energy transfer microscopy for probing mitochondrial deficiencies

Abstract

The autofluorescence of intact and respiratory deficiency yeast strains was measured using advanced microscopic techniques. Deficiencies in the inner mitochondrial membrane were correlated with an increase in NADH and flavin fluorescence. Since mitochondrial fluorescence was superposed by the luminescence of other intracellular sites, part of the cells were incubated with Rhondamine 123, a fluorescent mitochondrial marker. It could be shown that, depending on the excitation wavelength, Rhodamine 123 was excited either directly or by energy transfer from flavin molecules. The efficiency of this energy transfer may be used to probe the function of mitochondrial metabolism. Similarly, thionine and chloroaluminium phthalocyanine appear to be potential acceptors of excitation energy from mitochondrial cytochromes.