FLUORESCENCE OF 4-(PARA-DIMETHYLAMINOSTYRYL)-1-METHYLPYRIDINIUM IN THE LIVE CELL

Abstract

A fluorescent compound 4-(p-dimethylinostyryl)-1-methylpyridinium (DSM) was synthesized, having the absorption maximum about 450 nm and the fluorescence maximum .apprx. 590 nm in a water solution. A considerable increase of its fluorescence intensity is found in DNA solutions. The binding of DSM with membranes leads to a shift of its fluorescence maximum to 550 nm. Polychromatic properties of DSM (green fluorescence in membranes, rich yellow in energized mitochondria, and red-orange in nuclei) are found in DSM stained cells. DSM fluorescence is sensitive to changes in the energized state of cells: the uncoupler, dinotrophenol, or respiration inhibitors (cyanide and amital) cause a strong decrease in the DSM fluorescence intensity in mitochondria. Apparently DSM has a low toxicity with respect to cell energy: it had no influence on the mobility of Tetrahymena pyriformis during 23 h after staining. DSM may be used as a fluorescent probe for live cells.