Differentiated cell types derived from human embryonic stem cells (hESCs) may serve in the future to treat various human diseases and to model early human embryonic development in vitro. Fulfilling this potential, however, requires extensive development of methods and reagents for studying hESCs self-renewal and differentiation. One of the most widely used experimental approaches in the field of stem cell research is the identification of cell surface markers that can be used to prospectively define and isolate specific populations of stem cells and their progenitors. Here, we review an efficient method for generating monoclonal antibodies against cell surface antigens expressed by hESCs and stem cells at different stages of differentiation. This method may have profound implications for many aspects of hESC research and therapeutics.
