Regular Article :AATEX 3(3):85-93
The in vitro toxicity of 10 MEIC chemicals was determined using a fluorescence microscope-video camera-image processor system. Human lung carcinoma cells were loaded with rhodamine 123 which accumulates specifically in mitochondria in living cells. Rhodamine 123 fluorescence in mitochondria relative to that in the cytoplasm of the cells was measured after 3 hour treatment with the MEIC chemicals. Results showed that the ED50 values of the chemicals determined by this method were highly correlated with the corresponding values determined by the MTT (r=0.949) and lactate dehydrogenase-release assays (r=0.948) after 48 hours. This fluorescence-image processing was faster for measuring changes in mitochondrial function than the MTT assay, and is useful for measuring the direct toxic effects of chemicals on organelle's functions in situ.