Patent ID: 6743780
Filing Date: 2004-06-01
Classification: C12N

Abstract:
A method of delivering a stably maintained plasmid to a recipient organism comprising the steps of:a) culturing a host cell comprising: (i) a chromosomal gene essential for cell growth that is functionally associated with an operator susceptible to binding by a repressor produced by a second chromosomal gene, and (ii) a plasmid comprising an operator susceptible to binding by said repressor, wherein said repressor represses transcription of said chromosomal gene essential for cell growth in the absence of said plasmid, thereby inhibiting cell growth and wherein, when said plasmid is present in cells in sufficient numbers to titrate said repressor, said chromosomal gene essential for cell growth is expressed, thereby conferring a growth advantage on said cell; b) selecting cells containing the plasmid based upon cell growth; and c) transplanting said selected cells to said recipient organism.