The distinctive properties of human embryonic stem cells (hESCs) enable them to provide unique models to study the network of signaling pathways that regulate organogenesis, generate disease models, produce cells and tissues for therapies, and identify new drugs for treatment. Genetic modification of hESCs is a powerful tool to assist the above studies. Generation of lineage-specific fluorescent protein reporter hESC lines will greatly benefit investigators to monitor specific cell lineages in a live, easy, and timely manner. This technique will facilitate high throughput screening to identify molecules important in regulating specific cell fate commitment. In addition, such reporter cell lines enable researchers to enrich certain cell populations by fluorescent activated cell sorting (FACS) for either downstream biological analysis or in vivo applications. We have shown that hESCs can be stably transfected with a plasmid in which expression of the green fluorescent protein (GFP) is under the control of the Oct-4 promoter using chemical transfection. The expression pattern of transgenic Oct-4-GFP reflects that of endogenous Oct-4.
