Fig. 4From: Chromogenic Escherichia coli reporter strain for screening DNA damaging agentsReporter strain activation by chromium toxicity. In A the reporter strain was exposed to different concentrations of chromium solutions at two oxidation states, the highly toxic Cr(VI), and the less toxic form Cr(III). The table indicates the concentrations applied on each section of the plate. The experiments were carried applying directly 3 µL of each chromium solution. B shows the effect of lower concentrations of Cr(VI) and C shows higher concentrations of Cr(III). The clear area on each experiment indicates cell death. The purple halos indicate reporter strain activationBack to article page