Transient gene expression in mammalian cells provides reasonable amounts of recombinant proteins and antibodies which is sufficient for most applications. Nevertheless, when it comes to bulk productions for in vitro diagnostics or pre-clinical studies for biopharmaceutical development, the required amount of biological material often exceeds the yield that can be obtained through transient approaches. In this case, production from stable cell lines is highly advantageous since it allows easy generation of larger quantities of recombinant proteins and antibodies in measures of up to several grams per batch.

However, developing a stable cell line can be a time and resource intensive process with several bottlenecks that need to be overcome in order to ensure a good yield output.

After years of optimization work to counteract these bottlenecks, InVivo successfully established a proprietary platform for the development of stable cell lines using CHO (Chinese hamster ovary) cells as expression system.

We understand that every project is unique. Therefore, the entire process can be individually tailored to fit your specific requirements. After detailed rounds of discussion with our scientific experts, we help you decide if a stable cell line needs to be developed or if we can produce the required protein yields from a stable cell pool. With your final go, we start right away.

In many cases, sufficient material can be obtained through production from stable CHO cell pools instead of going all the way to produce a stable cell line. This approach is beneficial especially for time-sensitive projects, as recombinant antibodies and proteins become available within just a few weeks’ time. During stable transfection, the DNA of interest is integrated into the genome of the host cell to allow steady production of the target protein. However, the location and number of DNA insertions vary from cell to cell. This creates a pool of cells which all express the same protein or antibody, but with varying degrees of expression efficiency. When developing a stable cell line, the resulting cell pool then serves as starting point for single cell cloning and various screening processes, in which the clone with the highest productivity is identified and selected as basis for the stable cell line. By skipping the lengthy screening procedures and continuing with production directly from the cell pool, it is possible to reduce the costs and timeline of your project without compromising on the quality of the product.

Biopharmaceutical development

The development of biopharmaceuticals is very costly and production capacity in GMP facilities is often limited. To circumvent this problem and speed up research and development, a large part of the pre-clinical studies can be carried out using InVivo’s CHO cell pool concept based on a well-established cGMP-banked cell line, which can later be transferred into GMP facilities.
By using material from stable cell pools to characterize and evaluate potential drug candidates, it is possible to further reduce timeline and costs whilst optimizing the opportunity to process several of such potential targets in parallel.

If large amounts of recombinant antibodies or proteins are required in the long term, for example for the production of immunoassays for in-vitro diagnostics, then it is advisable to develop a stable cell line for subsequent productions. Starting from a selected stable cell pool, single cell cloning via limited dilution is performed and 100 monoclones are selected to undergo a multistep-screening process in order to identify 3 high-producer clones. In consultation with the customer, a final clone is selected to form the stable cell line. As stability of a cell line is very crucial, we perform clone stability testing to assure stable expression over time. Therefore, the selected monoclones are monitored over 60-70 population doublings and productivity is measured via biolayer interferometry (Octet) and analytical chromatography. This ensures that the final cell line produces the desired product reliably in large-scale for all future productions.