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Expired Canadian patentCanada

Analytical assay method

CA 2019980 C · Owner: Pb Diagnostic Systems, Inc. · Inventors: Maretsky, Donna R.; Blackwood, John J.; Inbar, Shai

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A method for determining the amount of an analyte in a sample fluid utilizes a multilayer assay element which comprises at least one reagent layer and a light-blocking layer. The assay method includes the steps of optically reading a signal producing species, e.g. a fluorescent label, a first time before the sample fluid is applied to the assay element and a second time at the, same wavelength and in the same location within the assay element after the sample fluid has been applied to the assay element and the sample analyte has interacted with the reagent(s) present in the assay element. The ratio of the two signals is taken and compared with that for known amounts of the analyte to …

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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 27, 1990 and granted August 23, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 27, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 27, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 27, 1990
GrantedAugust 23, 1994
Term endedJune 27, 2010
Patent numberCA 2019980 C
Classification (IPC)G01N21/31 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 27, 1990Patent grantedAug 23, 1994Term endedJune 27, 2010

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.