| 摘要 |
<p>This invention relates to a positive selection method, compounds useful for the positive selection and appropriate hosts. The method permits one to select a host, or auxotroph, which may be a prokaryote or an eukaryote, based on the ability of the host to express an enzyme(s) capable of catalyzing a reaction that converts a precursor molecule into a molecule or factor necessary for the host's survival. This invention encompasses methods useful to find new enzymes expressing a desired activity, methods of selecting host cells, methods of maintaining a plasmid within a host that do not utilize antibiotics, and methods of expressing proteins or other materials for commercial production purposes.</p> |
