Plasmid 20924: pEP4 E02S CK2M EN2L
  • used in the derivation of human iPS cells using non-integrating episomal vectors; expresses Oct4 and Sox2; Klf4 and Myc; Nanog and Lin28

  • Oct4 and Sox2; Nanog and Lin28; Klf4 and Myc

  • 4900

  • H. sapiens (human)

  • NM_002701 NM_002467 NM_004235 NM_024674 NM_024865 NM_003106

  • pCEP4
    (Search Vector Database)

  • Invitrogen

  • Episomal/EBNA

  • 11600

  • multiple

  • Unknown

  • multiple

  • Unknown

  • na List of Sequencing Primers

  • Ampicillin

  • Top10F'

  • 37

  • Top10 "Extremely" low copy number

  • Low Copy

  • View sequences (8)
  • View map

  • Notes from Addgene (1)

  • James Thomson



Oct4 and Sox2 are coexpressed under a strong EF promoter. Nanog and Lin28 are coexpressed under a separate (but identical) EF promoter. Klf4 and Myc are coexpressed under a strong CMV promoter. This plasmid contains EBNA-1 and OriP for limited maintenance in mammalian cells.

These plasmids were used at concentrations of >1.5 mg/ml. When preparing these plasmids for transfection, 3 low concentration maxipreps are done and the elution is combined in about 700 ul.

Note that there are some point mutations in the Klf4 gene, but they do not effect the function of this plasmid.

Addgene has sequenced a portion of this plasmid for verification. Full plasmid sequence is available only if provided by the depositing laboratory.

Article: Human Induced Pluripotent Stem Cells Free of Vector and Transgene Sequences Yu et al (Science. 2009 Mar 26. PubMed)

Please acknowledge the principal investigator and cite this article if you use this plasmid in a publication. Also, please include the text "Addgene plasmid 20924" in your Materials and Methods section.