A few years ago, I travelled to Zambia to backstop an emergency project that responded to one of the floods that hit part of that country. One of the consequences of this event was an expected increase in the prevalence of animal and plant diseases.
Evans Blue (EB) is one of the stains used to check the integrity of the cell membrane under the microscope. Normal cells keep the dye out, but it stains dead ones blue, indicating some pathology present and therefore a disease.
Fifty grammes of EB was about USD 250.00 (depending on the supplier). It is considered an expensive dye as blue is not an easy colour to find in nature.
So, when inspecting some of the purchases the project had done, I was rather surprised to find a bottle of 500g of the dye, produced in Zambia as, usually, EB is purchased from international chemical suppliers!
I believe that it was a rip-off from the local supplier that took advantage from the lack of knowledge of the client!