Background: pTurbo-Cre plasmids have been available to Washington University investigators via the core research facilities for several years. Its use is so effective that nearly all resulting transfected colonies have their PGK-Neo cassettes excised. Using these materials, the ES cell core has successfully produced homologous recombination in 1.4% of all clones isolated for genetic analysis, an excellent rate.

Technology Description: pTurbo-Cre is a recombinant plasmid engineered to express an extremely high amount of CRE-recombinase in embryonic stem (ES) cells. Many current protocols for generating recombinant ES cells require a positive selection step with a PGK-Neo cassette. This process improves the rate at which uncontaminated cells eventually go germline, however, the cassette can also cause a number of negative effects if left in the recombinant plasmid. For this reason, the marker regions are often flanked by Lox-P sites and later removed by CRE-recombinase.

Publications: Blood. September 2003; 102, 5: 1857-1865
The Journal of Immunology. 2005; 174: 2124-2131

File Number: CJ0058-1