Generation of retinal pigment epithelium and photoreceptor cells from human embryonic stem cells

This protocol describes a method to generate both retinal pigment epithelium (RPE) cells and photoreceptor cells by induction of human embryonic stem cells with Dkk1 and Lefty-A. Cell colonies containing retinal progenitor cells emerge after 45-50 days of differentiation. Long-term cultures of progenitor cells, give rise to RPE cells (25-30% of the colonies), whereas retinoic acid and taurine induction of retinal progenitor cells results in the formation of photoreceptor-like cells (10-20% of the cells).