This book is the updated English version of the 2006 German bestseller 'Zelluläre Diagnostik', a comprehensive presentation of flow cytometry and its applications. While some techniques of immunophenotyping by flow cytometry already are routine procedures in the laboratory, new methods for the functional characterization of cells, the analysis of rare cells, and the diagnosis of complex materials have only begun to win wide recognition. New approaches such as slide-based cytometry will lead to an increase in the use of cytometric techniques. Multiparameter approaches will further improve analysis. The book provides a comprehensive and detailed compilation of all aspects of flow cytometry in research and the clinic. For newcomers it offers a thorough introduction, for advanced users, specific protocols and interpretation assistance.