B12 enzyme immunoassay and sample pretreatment
CA 2071173 C · Owner: Staples, Mark A. · Inventors: Staples, Mark A.; Bartlett, Clifford R.; Liang, Edward Tung-Wu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Denaturing agents used to pretreat test samples for immunoassays are neutralized and deactivated by the addition of a treatment agent which is a combination of a buffering agent in acid form and an agent for converting the sulfhydryl groups of the denaturing agents to a non-active form such as disulfides or alkylthio groups. The treatment agent serves this function without having sufficient denaturing activity by itself to interfere with subsequent steps of the assay procedure. Also disclosed is a protocol for a vitamin B12 assay which involves a sequential rather than competitive binding of the B12 with excess intrinsic factor followed by the binding of excess enzyme-labeled B12 to any …
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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 June 12, 1992 and granted May 25, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 2014.
- 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.