Microbial cell surface properties play a central role in controlling phenomena such as bacterial adhesion and biofilm formation (on stent or on prosthesis for example). The quantification of these properties and the understanding of interactions with antibacterial compounds remain difficult, in view of the complex and dynamic nature of the cell wall constituents. Various approaches, macroscopic, microscopic or molecular, have been developed. Two of them interest us today: (i) microelectrophoresis, which permits to evaluate surface modifications by measuring eletrophoretic mobility; and (ii) atomic force microscopy (AFM), a high resolution imaging device, which allows investigations at nanometric scale. After brief presentation of principles and instrumentations, the aim of this article is to present the different applications of these techniques in Microbiology, and to discuss interest of these tools in order to investigate mechanism of action of antibacterial compounds.