Toluidine blue, oxidation with

Mechanisms involving glycol bond fission have been proposed for the oxidation of vicinal diols, and hydride transfer for other diols in the oxidation of diols by bromine in acid solution.The kinetics of oxidation of some five-ring heterocyclic aldehydes by acidic bromate have been studied. The reaction of phenothiazin-5-ium 3-amino-7-dimethylamino-2-methyl chloride (toluidine blue) with acidic bromate has been studied. Kinetic studies revealed an initial induction period before the rapid consumption of substrate and this is accounted for by a mechanism in which bromide ion is converted into the active bromate and hyperbromous acid during induction and the substrate is converted into the demethylated sulfoxide. 

For conventional electron microscopy, processing was performed as described in Tsukada et al. (2001) and Yamashima et al. (2003). Small specimens of hippocampus were fixed with 2.5% glutaraldehyde for 2 h and subsequently with 1% osmium tetroxide in TBS for 1 h at 4°C, dehydrated in ascending ethanol series, incubated in propylene oxide (2 x 15 min) and finally embedded in epon-araldite mixture. Usually, between four and eight semithin (1 pm) sections were stained with tolui-dine blue for the light microscopic observation. After trimming upon observation of toluidine blue staining, the ultrathin sections were stained with uranyl acetate (10 min) and lead citrate (5 min) for the electron microscopic observation (JEM H-600, Hitachi, Tokyo). 

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