Expression systems
As no single system is ideal for each and every recombinant protein, GTP offers a large variety of expression systems to best meet your needs.
When necessary, we will assist you in choosing the most appropriate expression system according to your protein and the final objective of your project.
The systems we routinely use at GTP are listed below, but we regularly work with “exotic” systems and would be pleased to consider any request.
We are equipped for culture sizes up to 50L for microbial fermentation and up to 100L for cell culture. Should larger capacities be required for a specific project, we have access to larger fermenters.
E. coli
With 40% of our projects using Escherichia coli as the expression platform, we have extensive experience producing a diversity of proteins (over 300 different proteins) in this system.
For research projects, we use standard commercial expression vectors and strains. When the protein is intended for an industrial application, we offer our optimized and IP-free vectors that are designed for improved expression and stability.
Our services include small-scale expression trials and development of batch, fed-batch and chemostat fermentation strategies.
Learn more about our expertise with E. coli
L. lactis
We have developed a proprietary expression system, LactXpress, including a collection of strains and expression vectors. This Gram+ bacteria represents an alternative and innovative system for the production of high added-value recombinant proteins such as vaccine or therapeutic candidates.
We offer access to our LactXpress system through licensing and will evaluate it for your specific protein by performing a feasibility study.
P. pastoris
With its great potential, P. pastoris can be the system of choice for many proteins and applications.
At GTP, we use standard commercial P. pastoris strains and vectors. Our services include generation and selection of high and hyper-producing clones and the development of fed-batch fermentation strategies.
Mammalian cells
We offer expression with CHO and HEK cell lines using classical techniques: transient transfection at a small-scale or generation of stable cell lines when large-scale is required. For CHO cells, we also offer the new CHO-Xpress technology, which combines the advantages of transient and stable expression.
Small-scale cultures are performed in flasks and in-house we can handle a scale-up to 100L in disposable bioreactors. Cell cultures can be performed in batch, fed-batch or in perfusion mode.
Learn more about our CHO-Xpress technology
Insect cells
An interesting alternative to mammalian cells for the production of proteins for research, we have performed numerous productions with insect cells. We offer expression in Sf9 or High Five cells with the baculovirus system.
Our services include small-scale expression trials to define the best expression conditions and scale-up to 100L.
