QD Molecular Markers In a project that is primarily funded through the Department of Energy’s Genome to Life initiative, we are developing semi-conductor quantum dots as intracellular labels for both light and electron microscopy. Because of their brightness, unique spectral characteristics, chemical stability and resistance to photobleaching, the quantum dots provide an excellent tool for multi-color long-term optical imaging studies. In addition, the electron density of the dot core could make it feasible to use the same tags as high-resolution markers in electron microscopy. The scope of this project includes the development of novel coatings for core-shell semi-conductor quantum dots, the optimization of delivery systems into a variety of organisms including E. coli, S. cerevisiae, and eventually mammalian cells, and the testing of various protein tagging systems.