Pre-made lentiviral particles bicistronically express two individual proteins: nuclear permeable CRErecombinase and the RFP marker under the same enhance EF1a promoter. CRE contains a NLS (nuclear localization signal)at its N-term. Thisnuclear permeantCREincreases the recombination events in vivo. A Neomycin marker was expressed under RSV promoter. Particles allows to sort or select transduced cells for long term expression via RFP signal or via Neomycin (G418) antibiotic selection.

Cre protein, from bacteriophage P1, catalyzes recombination between 34 base pair target sequences,named lox sites. CRE lentiviral particlescancatalyzethe jointing event In Vivoin the presence oflox sites. Purified CRE enzyme can joint individual plasmids containing lox sites.

CRE and RFP are constitutively expressed in high levelindependentofcell types.RFP signal provides a convenient, realtime monitoring theparticles performance. See product manual for details (.pdf).