This post accompanies a poster I presented as part of the Amgen Scholars program, a diary of my time at the LMU in Munich will be posted shortly.
Embryoid bodies (EBs) are three-dimensional aggregates of pluripotent stem cells, stem cells within embryoid bodies undergo differentiation and cell specification along the three germ lineages – endoderm, ectoderm, and mesoderm – which comprise all somatic cell types.
As a result of the three-dimensional EB structure, complex morphogenesis occurs during EB differentiation, including the appearance of both epithelial- and mesenchymal-like cell populations, as well as the appearance of markers associated with the epithelial-mesenchymal transition. Additionally, the inductive effects resulting from signaling between cell populations in EBs results in spatially and temporally defined changes, which promote complex morphogenesis. Tissue-like structures are often exhibited within EBs, including the appearance of blood islands reminiscent of early blood vessel structures in the developing embryo, as well as the patterning of neurite extensions (indicative of neuronal organization) and spontaneous contractile activity (indicative of cardiomyocyte differentiation).
Hanging Drop Technique
We used the hanging drop technique to form embryoid bodies. This is an incredibly simple process which doesn’t require any specialist materials or training. First, droplets of a single cell suspension are placed on the underside of a 10 cm culture dish and aggregates left to form for 4 days. On the fourth day, embryoid bodies are transferred to ultra low adhesion plates to continue their growth phase. On the seventh day, the multicellular aggregates are transferred to gelatinised culture plates where micro-tissues begin to form.