Il-21 production in prokaryotic hosts
CA 2507817 C · Owner: Holderman, Susan D. · Inventors: Liu, Hong Y.; Chan, Chung; Holderman, Susan D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The expression vectors and methods using an E. coli expression system for the large scale production of IL-21 are described. The vectors utilize the IL-21 coding sequence with specific changes in nucleotides in order to optimize codons and mRNA secondary structure for translation in E. coli. . Using the expression vectors, the IL-21 gene was produced in E. coli to a level of greater than 1 g/L in fed batch fermentation. Also included are OmpT deficient E. coli strains transformed with an IL-21 expression vector.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 12, 2003 and granted April 22, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 12, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 12, 2025.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.