Differentiating Mouse Embryonic Stem Cells into Embryoid Bodies in AggreWell Plates

Embryonic stem (ES) cells can develop into many types of differentiated tissues if they are placed into a differentiating environment. This can occur in vivo when the ES cells are injected into or aggregated with an embryo, or in vitro if their culture conditions are modified to induce differentiation. Many times ES cell differentiation proceeds through an intermediate stage called the embryoid body (EB). EBs are round structures composed of ES cells that have undergone some of the initial stages of differentiation. EBs can then be manipulated further to generate more specific cell types. The method described here makes use of commercially available AggreWell 400 plates with prefabricated indentations that cradle each EB. Although these plates are relatively expensive, they may be suitable for some high-throughput experiments. This protocol describes the preparation of embryoid bodies of defined size and shape in a large-scale format (approximately 1200 embryoid bodies per preparation).