_Tetrahymena thermophila_ is emerging as a powerful experimental system for functional genetics. The ciliated protozoan offers numerous advantages, not the least of which is the ability to eliminate any specific gene of interest and then to evaluate the effect of that mutation on the living cell. Past investigations with _T. thermophila_ have yielded several key discoveries, including dynein, catalytic RNA, and telomerase. This volume is a comprehensive resource for using _Tetrahymena_ in the laboratory and is aimed at persons already experienced, as well as newcomers to the organism. It covers both the biological background and essential protocols for investigators rapidly turning to _Tetrahymena_ as the experimental system of choice. Key Features * Contains both theoretical and practical issues in 30 chapters contributed by the world authorities on _Tetrahymena_ * Indispensible for both the novice and the experienced researcher * Overviews the history, cell biology, and genetics of the organism * Describes essential protocols on the growth of cells, genetic techniques, and how to look at the cells with the microscope * Illustrates how the methods can be applied to solve various cell biological problems * Reviews recently developed strategies for altering gene expression