The interest of using of microwave in the biomedical field is growing since few years, especially for application dedicated to cellular analysis. Indeed, due to its size and cytoplasm content, a biological cell can be considered as a micrometric dielectric particle. Probing this cell thanks to microwave signal can allow to access to data on its biological and physical content. This paper illustrates the interaction capabilities of microwave with cell cytoplasm in order to extract their intrinsic dielectric properties. In this objective, some tunable resonant frequency biosensors have been designed in order to characterize cancer cells.