Electron microscope identification of mesosomes in some water strains of Leptospira by reduction of tetrazolium chloride to formazans.

Rounded granules protruding from the external surface of some water Leptospira strains and considered as mesosomes were studied by electron microscope and by means of the intravital reduction of tetrazolium chloride. Satisfactory results were obtained with two of the strains studied. It appears that neither the culture medium nor the age of the culture have any influence on the unusual position of the mesosomes.