Isolating specific cells or fractionating viable cell populations is an essential step of many of the techniques used across a wide range of biological and related disciplines. This text aims to inform those working in all areas of the biological sciences of the methods which are available to them and which is likely to be the most useful. The contributing authors have provided a comprehensive guide to the methods used to prepare cell suspensions and to separate viable cells depending on their different characteristics - such as size, density, surface charge and immunological identity. Each chapter offers direct practical guidance for the various techniques and describes the advantages and limitations of each. Reproducible protocols, hints and tips for success and troubleshooting suggestions are provided.