Embryonic stem cells (ESCs) are pluripotent and can differentiate into neural precursor cells (NPCs) and subsequently into neurons under certain conditions1. ESC-based neurogenesis provides the best platform to mimic neurogenesis, thus serving as a useful tool for developmental biology studies and potentially aid in regenerative medicine2,3. In the past decades, many strategies have been reported for inducing embryonic neurogenesis, such as the transgenic method4, using small molecules5, using a 3D matrix microenvironment6, and the co-culture technique7. However, most of these protocols are either condition limited or hard to operate, thus they are not suitable for usage in most laboratories.
To find an easy to operate and low cost method to achieve efficient neural differentiation from mESCs, a combinatorial screening strategy was used here. As described in Figure 1, the whole process of embryonic neurogenesis was divided into 2 phases. Phase I refers to the differentiation process from mESCs into NPCs, and phase II relates to the subsequent differentiation from NPCs into neurons. Based on the principles of easy operation, low cost, easily available materials and high differentiation efficiency, seven protocols in Phase I and three protocols in Phase II were chosen based on the traditional adherent monolayer culture system or embryoid body formation system8,9. The differentiation efficiency of protocols in both phases was evaluated using cell morphology observation and immunofluorescence assay. Through combining the most efficient protocol of each phase, we established the optimized method for neural differentiation from mESCs.