Protocol for generating a 3D culture of epiblast stem cells

Mouse gastrulation entails concomitant changes in cell fate, tissue shape, and embryo size. The use of a reproducible in vitro system is crucial for dissecting the mechanisms that coordinate these events. Here, we present a protocol for generating a 3D culture of epiblast stem cells (3D EpiSCs), which grow as epithelial spheroids mimicking key features of the gastrulating mouse embryonic epiblast. We describe steps for spheroid formation, growth, and passaging, followed by imaging or further downstream analyses. For complete details on the use and execution of this protocol, please refer to Sato et al.¹.