A vector based on the SV40 origin of replication and chromosomal S/MARs replicates episomally in CHO cells

Nucleic Acids Res. 1999 Jan 15;27(2):426-8. doi: 10.1093/nar/27.2.426.


We have developed an episomal replicating expression vector in which the SV40 gene coding for the large T-antigen was replaced by chromosomal scaffold/matrix attached regions. Southern analysis as well as vector rescue experiments in CHO cells and in Escherichia coli demonstrate that the vector replicates episomally in CHO cells. It occurs in a very low copy number in the cells and is stably maintained over more than 100 generations without selection pressure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Viral, Tumor / genetics
  • CHO Cells*
  • Cricetinae
  • DNA Replication*
  • Genetic Vectors / biosynthesis*
  • Humans
  • Interferon-beta / genetics
  • Nuclear Proteins / genetics
  • Plasmids / biosynthesis*
  • Replication Origin
  • Simian virus 40 / genetics


  • Antigens, Viral, Tumor
  • Nuclear Proteins
  • Interferon-beta