This second edition provides new and updated chapters useful for the study of Regulatory B cells. Organized in four sections, chapters detail basic methods for the isolation and immunophenotypical analysis of these cells, experimental approaches for the ex vivo generation/expansion of IL-10 producing B cells, molecular biology techniques for the analysis of IL-10 expression and production, and animal models mimicking pathologic settings. Written in the highly successful Methods in Molecular Biology series format, chapters include an introduction to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, as well as tips on troubleshooting and avoiding known pitfalls.