The first section of this volume is aimed to provide a comprehensive review of the many varied and often empirically derived techniques and procedures currently in use to produce monoclonal hybridoma cell lines and to characterize the antibodies secreted. The goal has been achieved with the chapter contributed by Zola and Brookes who, as each step in the process of hybridoma production and antibody characterisation is reviewed, have provided an experimental procedure found to be satisfactory in their laboratory.The second section of this volume is designed to provide a review of areas in which monoclonal hybridoma antibodies have been of particular advantage. This is a rapidly advancing field which could not be thoroughly reviewed in a single volume.