Isolation, Characterization, and Utilization of T Lymphocyte Clones is a summary of information regarding T lymphocyte clones, including their usefulness. Organized into nine parts, the book begins with discussions on the soluble factors that can influence the growth of cloned T cells and the utilization of T cell hybridomas for analysis of T cell functions, emphasizing the biochemical and functional properties of helper and suppressor factors. The book then looks into the analysis of T cell clones and hybridomas using techniques of somatic cell genetics. The clonal analysis by limiting dilution, the characteristics of murine T cell clones reactive with alloantigens and soluble antigens, and the human T cell clones are described as well. This volume is valuable to those interested in the field of cloning of immunocompetent T cells.