Total internal reflection imaging of microorganism adhesion using an oil immersion objective

In this paper, we report the results of total internal reflection microscopy investigations of the interaction of two types of microorganisms: Saccharomyces cerevisiae and Escherichia coli with substrates. It is shown that with this method qualitative and quantitative information about cells–substrate interaction can be obtained. One can easily make a difference between attached and non-attached as well as between dead and alive cells, and more generally can follow the dynamics of the process of cells’ attachment to substrates. Quantitative information about the cell size and cell–substrate distance is obtained by using a model in which yeast cells and bacteria are approximated by ellipsoids, and multiple reflections of the evanescent waves between the cells and the substrate are neglected.