Patents Examined by C. Low
  • Stable high copy number plasmids
    Patent number: 4966840
    Abstract: DNA plasmids are described which are selected mutants in which an altered repressor gene leads to high copy number replication. Elements in the plasmids are modified in such a way that readthrough expression of heterologous DNA inserted in the plasmid will not continue into the replication primer strand. Deletions resulting from interference with replication primer strand transcription are thereby avoided.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: October 30, 1990
    Assignee: Cetus Corporation
    Inventor: David H. Gelfand