The effects of ethidium bromide were tested on isolated cockroach interganglionic connectives, either with the perineurium intact or desheathed. Intact connectives showed small, reversible depolarizations in response to 25 mM-ethidium. Desheathed connectives showed much larger, concentration-dependent depolarizations and the membrane potentials repolarized only slowly after washing out ethidium...

Free and ethidium bromide (EB) complexed alkali denatured T7 DNA molecules were renatured at 58 and 62 degrees C respectively for 1--3 h. The structures of the renaturation products of the free candidates were as usual showing native like, branched and unrenatured DNA whereas the structures of the ethidium bromide complexed one were somewhat different, showing non-renatured loop-like and entang...

Tertiary structure changes in plasmid DNA, induced by ethidium bromide intercalation, have been observed in aqueous solutions by the use of an atomic force microscope. A relaxed closed circular pBR322 molecule became a positively supercoiled complex on the drug binding. The supercoiling always resulted in an interwound (or a plectonemic) form, but never a solenoidal (or a toroidal) form. A quan...

A Streptococcus pneumoniae strain selected for resistance to ethidium bromide demonstrated enhanced energy-dependent efflux of this toxic dye. Both the ethidium resistance and the ethidium efflux could be inhibited by the plant alkaloid reserpine. The ethidium-selected cells demonstrated cross-resistance to the fluoroquinolones norfloxacin and ciprofloxacin; this resistance could also be comple...

Analysis of electron autoradiographs from the nerve cord of the insect, Periplaneta americana (L.) shows a significant incorporation of 3H-labelled protein in the axons. The axonal activity is greatly reduced after treatment of the cord with the glial toxin ethidium bromide. This is interpreted as substantiating the possibility that adaxonal glia can transfer proteins to the axons.