[Determining the relative content of cisplatin in cells by acridine orange fluorescence intensity]

The fluorescence intensity of acridine orange (AO) dye bound to living human leukocytes, rat leukocytes, and Pliss lymphosarcoma cells of rat has been studied by fluorescence microscopy. The cell suspension of each test was divided into two parts, to one of which the drug cisplatin was added to a final concentration of 0.1 μg/mL and the mixture was incubated for 20 - 60 min. Acridine orange was then added and the average intensity of red and green fluorescence of cells was determined. The brightness of AO in the green region of the spectrum was reduced approximately 3-fold (p = 0.001) in cells with cisplatin. In the red region of the fluorescence, differences in the brightness of cells with and without cisplatin were not observed. These data indicate that a decrease in the brightness of green fluorescence of AO can be a test for the presence of cisplatin in cells.