Stem cells have the ability to differentiate into all types of cells within the body, thus have great therapeutic potential for regenerative medicine to treat complicated disorders, like Parkinson's disease and spinal cord injury. There will also be many applications in drug development. However, several roadblocks, such as safety issues and low efficiency of pluripotent stem cell (PSC) line derivation need to be resolved before their clinical application. This thesis focuses on these two areas, so as to find methods to overcome the limitation. It covers deriving embryonic stem cells (ESCs)...