N2 Supplement-A, containing iron-rich human transferrin, was developed for the in vitro differentiation of mouse or human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells. Different neuronal subtypes can be generated when human ES/iPS cell-derived neural progenitor cells are cultured in BrainPhys™ Neuronal Medium (Catalog #05790) supplemented with N2 Supplement, NeuroCult™ SM1 Neuronal Supplement (Catalog #05711) and other factors. N2 Supplement-A may be used with ES-Cult™ Basal Medium-A for the in vitro differentiation of mouse embryonic stem cells (mESCs) and mouse induced pluripotent stem cells (miPSCs) to neural and pancreatic-like cell types. N2 Supplement-A is provided as a 100X concentrate.