This volume details techniques involved in the study of endosymbionts. Chapters divided into four sections detail isolation, maintenance of diverse endosymbionts, classical microscopy, staining, PCR, FISH, flow cytometry, next-generation sequencing, endosymbionts, metabolites, and bacterial endosymbionts in insects. Step-by-step protocols are complemented by personal notes, precautions, and specifying the reagents to be used in each step to ensure the repeatability of the procedure across labs. Authoritative and cutting-edge, Endosymbionts aims to empower researchers to expand the frontiers of endosymbiosis research and unlock new possibilities for science.