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pSI Mammalian Expression Vector

Constitutive Expression of Cloned DNA Inserts from SV40 Promoter in Mammalian Cells

  • SV40 enhancer/promoter region allows strong, constitutive expression in most cell lines
  • Multiple cloning sites exist for easy insertion of cDNA
  • Synthesize transcripts in vitro using the T7 RNA polymerase promoter or generate single-stranded DNA in E. coli using the f1 origin of replication


Catalog number selected: E1721

$ 395.00
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pSI Mammalian Expression Vector
$ 395.00
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The pSI Mammalian Expression Vector promotes constitutive expression of cloned DNA inserts in most mammalian cells. The vector is maintained as an episome in cells expressing the SV40 large T antigen, leading to even higher levels of expression. A β-globin/IgG chimeric intron located downstream from the enhancer/promoter region can further increase expression. In addition, the late SV40 polyadenylation signal increases the steady-state level of RNA approximately fivefold more than the early SV40 polyadenylation signal.

The major difference between the pCI and pSI Mammalian Expression Vectors is the enhancer/promoter region controlling expression of the inserted gene. The pSI Expression Vector contains the simian virus 40 (SV40) enhancer and early promoter region. This vector can be used for both transient and stable expression of genes. For stable expression, the pSI Vector must be co-transfected with an expression vector containing a selectable gene for mammalian cells.


  1. Gluzman, Y. (1981) Cell 23, 175–82.
  2. Brinster, R.L. et al. (1988) Proc. Natl. Acad. Sci. USA 85, 836–40.
  3. Choi, T. et al. (1991) Mol. Cell. Biol. 11, 3070–4.
  4. Palmiter, R.D. et al. (1991) Proc. Natl. Acad. Sci. USA 88, 478–82.
  5. Carswell, S. and Alwine, J.C. (1989) Mol. Cell. Biol. 9, 4248–58.



pSI Mammalian Expression Vector GenBank® Accession Number U47121 and vector sequence text file.


What's in the box?

Item Part # Size

pSI Vector

E172A 1 × 20μg


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Download SDSPDF (178 KB) – English (United States)

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Use Restrictions

For Research Use Only. Not for Use in Diagnostic Procedures.

Storage Conditions


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