Transient expression

While plants can be transformed with a construct introduced into Agrobacterium tumefaciens via agroinfiltration or floral dip, most animal cells would require a viral vector.

[3] This rapid generation small quantities of recombinant proteins can be applied towards evaluating their potential as drug candidates or examining their integrity of constructs during stages of vector development.

Additionally, transient expression can be a useful tool when aiming to optimize selected parameters before undergoing the time-consuming process of scale-up in stably transfected cells.

However, since successful integration of a DNA vector into the chromosome is a rare occurrence, this process is more difficult and time-consuming, and is reserved for large-scale protein production, gene therapies, and long-term pharmacology studies.

Furthermore, since the parent tumor-inducing plasmid in Agrobacterium strains have been disarmed and only non-reproductive cells have been modified (as opposed to germ-line modifications), the process is considered environmentally harmless.

[10] Advantages of using this cell line include their high rates of transfection and ability to grow in a serum-free medium, which results in reduced cost and lowered risk of contamination with animal-derived material typically found in serum.

[11] CHO cells are preferable for transient expression due to their easy industrial scale-up, versatility for the production of diverse biomolecules, and low risk of infection of human viruses, among other advantages.

(a) Depicts the process of disarming of the Agrobacteria tumor-inducing plasmid and fusion with plant viral regulatory sequences. (b) Depicts co-expression via infiltration of several Agrobacteria cultures containing separate binary vectors or cultures possessing single vectors containing multiple expression cassettes.