[1-methoxy-5-methylphenazinium-methylsulfate--a light stabile redox mediator in the histochemistry (author's transl)]

1-Methoxy-5-methylphenazinium methyl sulfate (MPMS) was tested for use as redox mediator in histochemistry of dehydrogenases. Aqueous solutions of MPMS are absolute lightstable. Like PMS or Meldola Blue the succinate dehydrogenase reaction was increased by MPMS. In an non-enzymatic NADH-NBT-test the reaction rate of MPMS exceeds the rates of PMS or Meldola Blue.