The vector is designed to optimize expression of the protein of interest and minimize any unfavourable impacts on cell growth for the utilized CHO DG44 cells. The vector, which is based on the DHFR amplification system, has been constructed by Sartorius Stedim Cellca using well-known elements ensuring freedom to operate. The DHFR (Dihydrofolate reductase) is expressed only in low levels, which results in a high selection stringency and increases the probability of isolating high producing clones after the selection process.
The genetic elements of the expression cassette have been carefully selected and the distance between the genes has been optimized. The DHFR selection system is suitable for both monomeric and dimeric products and utilizes S/MAR elements for enhanced, stable expression as well as optimal signal peptides for enhanced secretion.
The vector map below shows the structure and elements of the Expression Vector.