Calcium Signaling Protocols is a comprehensive textbook that focuses on the regulation of intracellular calcium (Ca2+). The first edition of this work laid the foundation for numerous studies in this field, and the present second edition offers an updated and expanded perspective. With a total of 22 chapters written by experts, the book covers a wide range of topics, including the fundamentals of theory and the application of fluorescent indicators. The structure of the book is divided into six parts, each addressing different aspects of calcium signaling, including the measurement of calcium channel activities and the analysis of calcium release from intracellular stores. This extensive collection of protocols and techniques serves as a valuable reference for researchers and professionals engaged in calcium signaling in biological systems.