Hello all,

I am currently trying to establish a protocol to differentiate iPSCs to Retinal Pigment Epithelium. I have set up an array of conditions to establish which is the best method to establish the cells. Some cells very early undergo epithelial to mesenchymal transition while others have came along nicely and are polyclonal. I have previously tested and the cells are positive for RPE markers including RPE65, ZO-1, VEGFR. However I am having difficulty in that my cells are not showing any signs of pigmentation. I am currently culturing my cells in Miller Media with 1% FBS. I plan in the forthcoming weeks to perform IF and RT-PCR to determine if the cells test positive for MITF and PEDFR.

However in the meantime does anyone have any suggestions as to why my iPS-RPE may not be pigmenting and how to induce such? Any comments are widely appreciated!