- How does Selexis Genetic Elements work?
- Could Selexis Genetic Elements be expected to boost productivity by 2, 4, 6-fold, etc?
- What cell types and what promoters have been tested with Selexis Genetic Elements?
- How many cell lines have been created with Selexis Genetic Elements?
- Does Selexis have statistics on successes per attempt, etc?
- How stable are the cell lines made with Selexis Genetic Elements?
- How many cell lines have been taken forward into the bioreactor stage?
- Anyone using this system with a product in clinical trials?
- Are there regulatory issues concerning the use of the Selexis vectors?
- Are there any sequences of unknown function in the Selexis vectors?
- How to submit questions or comments about your technology?
- I have published a paper using Selexis Genetic Elements. How do I get this information to Selexis?
1. How does Selexis Genetic Elements work?
Selexis Genetic Elements can be used with any expression vector system. So far, several expression vectors were successfully tested along with Selexis Genetic Elements. The genetics of the host cell line is not altered, except for the production of the recombinant protein.
To establish a novel high producing cell line, Selexis Genetic Elements (from 1.6Kb to 4Kb in length) are used to control the promoter accessibility of the expression cassette. For this reason, Selexis Genetic Elements increases the amount of recombinant protein produced. In addition, the increased number of clones that have integrated the transgene cassette (post transfection) allows a fast isolation of high-yield expressing cell clones.
This 3rd generation production technology represents significant savings both in the production of research grade materials (e.g. R&D) and in the selection of very high producing single cell clones for large-scale manufacturing.
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2. Could Selexis Genetic Elements be expected to boost productivity by 2, 4, 6-fold, etc?
For antibody production, Selexis has demonstrated that Selexis Genetic Elements was able to boost the productivity of cell clones by a factor of up to 20.
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3. What cell types and what promoters have been tested with Selexis Genetic Elements?
Selexis Genetic Elements has been tested in a variety of cell types including: CHO, HEK 293, BHK, C2C12, and a B cell derivative. We have tested different versions of the CMV promoter as well as the ubiquitin promoter and the SV40 early promoter.
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4. How many cell lines have been created with Selexis Genetic Elements?
Selexis with its partners have tested over 30 cell lines. These include cell lines expressing Green Fluorescent Protein (GFP), various monoclonal antibodies, a clotting factor, the EGF receptor, EPO as well as membrane bound receptors.
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5. Does Selexis have statistics on successes per attempt, etc?
With all of the 30 cell lines made by Selexis and its partners the increase in productivity, when using Selexis Genetic Elements, ranged from 2 fold to 15 fold depending on the release of Selexis Genetic Elements used. These data are based on many selection procedures performed by independent researchers and laboratories worldwide, and include analysis of numerous cell pools and clones.
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6. How stable are the cell lines made with Selexis Genetic Elements?
Using Selexis Genetic Elements, Selexis has tested the stability of both pools of transfected cells as well as individual clones. The individual clones were stable, as assayed by specific productivity, for over 14 months. With the second generation of the Selexis Genetic Elements technology (Selexis Genetic Elements II), transfected pools expressing the GFP were stable for at least 6 months. This stability testing is still in progress.
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7. How many cell lines have been taken forward into the bioreactor stage?
Over 10 cell lines have been scaled up and tested in the bioreactor. The Selexis Genetic Elements cell lines were compared with cell lines made the traditional manner. The cell lines made with Selexis Genetic Elements were found to maintain the high level of expression and yield stable production at this high level during optimization in the bioreactor. Therefore the yield improvement seen during the creation of the cell lines was seen to translate into increased yields in the bioreactor.
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8. Anyone using this system with a product in clinical trials?
As of the end of 2007, two companies have taken cell lines developped with the Selexis technologies forward to produce cGMP material for use in the human clinical trials.
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9. Are there regulatory issues concerning the use of the Selexis vectors?
Detailed information regarding the vector and the Selexis genetic elements used in the expression vectors, are provided by Selexis to clients for any regulatory filings. This information includes a description of the source and function of the component parts of the vector, e.g., antibiotic resistance genes, promoters, enhancers and Selexis genetic elements.
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10. Are there any sequences of unknown function in the Selexis vectors?
Selexis provides a step-by-step description of the assembly of all gene fragments present in the vector, including the Selexis genetic elements, to form the final gene constructs. The entire sequences of the expression vectors, including Selexis genetic elements, are defined, satisfying the requirements of the "points to consider" document from the FDA.
Download more information (pdf, 280k)
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11. How to submit questions or comments about your technology?
You can email us directly at info@selexis.com
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12. I have published a paper using Selexis Genetic Elements. How do I get this information to Selexis?
Please send your paper along with full contact information to info@selexis.com
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