The pcDNA™3.3-TOPO® TA Mammalian Expression Vector enables expression of exceptionally high levels of recombinant protein in adherent-or suspension-adapted mammalian cells.
The pcDNA™3.3-TOPO® vector contains a modified, enhanced CMV promoter that enables extremely high protein expression. The vector is ideal for large-scale protein production, especially when used in combination with our FreeStyle™ MAX CHO or 293 Expression Systems. We expressed several proteins and observed 8–30 mg/L of recombinant protein produced using our FreeStyle™ systems (Figure 1).
Figure 1. High yields of recombinant protein. We used pcDNA™3.3-TOPO® vector to clone and express milligram levels of erythropoietin (EPO), Factor IX (FIX), and IgG in FreeStyle™ CHO-S cells. pcDNA™3.3-TOPO® constructs containing the relevant PCR-derived gene sequences were transfected into FreeStyle™ CHO-S cells in 30 mL volumes. Heavy and light chain genes were co-transfected for IgG expression. Four to six days posttransfection, EPO and FIX were quantified using immobilized goat anti–human IgG antibody. Each bar shows the average of two expression runs.
Figure 2. pcDNA™3.3 vector map. The latest version in the pcDNA vector family, pcDNA™3.3 offers you the flexibility to express a native protein or add your favorite purification tag to the gene of interest prior to TOPO® cloning.
Our pcDNA™3.3 vector incorporates TOPO® cloning technology, which removes time-intensive and unreliable steps from your cloning workflow, allowing you to perform bench-top cloning reactions in typically just 5 minutes. With up to 95% recovery of your desired clone, you always have the clone you need for downstream experiments.
Figure 3.We cloned and measured expression of luciferase (panel A) and ß-galactosidase (panel B) in pcDNA™3.3-TOPO® vector, pCI and pCMV-Script® vectors. After transient transfection into adherent GripTite™ 293 MSR cells, ß-galactosidase activity and luciferase activity is 2- and 5-fold higher, respectively, using pcDNA™3.3 vector compared to competitor vectors. Error bars shown represent standard deviation (n = 6).
The pcDNA™3.3 TOPO® TA Cloning Kit includes high-efficiency One Shot® TOP10 Competent Cells for superior cloning performance. Our OptiCHO™ Antibody Express Kit, which includes the pcDNA™3.3 TOPO® TA Cloning Kit, enables stable cell line creation and antibody production in a serum-free dihydrofolate reductase-deficient (DHFR–) Chinese hamster ovary (CHO) DG44 cell line.
For Research Use Only. Not for use in diagnostic procedures.