Accueil > Publications > Recherche par années > Années 1990 > 1997

Favard, C ; Pager, J ; Locker, D ; Vigny, P

Incorporation of ethidium bromide in the Drosophila salivary gland approached by microspectrofluorometry : Evidence for the presence of both free and bound dye in the nuclei of cells in viable conditions

European Biophysics Journal With Biophysics Letters 25 (4) 225-237

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Abstract :

The incorporation of 10(-6) M ethidium bromide (EB) was studied in viable Drosophila melanogaster salivary glands with a spatial resolution reaching a few mu m(3), using a confocal laser microspectrofluorometer designed for spectral analysis. Spectra were recorded with the 514 nm Argon laser line during excitation times of 1 second (20 mu W on the preparation) at 5 min intervals for 30 or 60 min, either at points in determined cell sites or serially throughout the cells. The fluorescence intensity time-course indicated that the EB intake was not an all-or-none process, but rather a graded, sensitive indicator of the functional state of the cell. On the micrometer scale, the cytoplasm behaved as an homogeneous substrate with the fluorescence intensity depending on EB intake and intracellular diffusion. In the nucleus ? however, localized enhancement of the emission intensity was observed.