Patents by Inventor Hashem Akhavan-Tafti

Hashem Akhavan-Tafti has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040166539
    Abstract: Methods and compound useful for detecting a source of hydrogen peroxide are disclosed wherein a signalling compound of the formula: 1
    Type: Application
    Filed: February 20, 2003
    Publication date: August 26, 2004
    Inventors: Hashem Akhavan-Tafti, Robert A. Eickholt, Kenneth S. Lauwers, Richard S. Handley
  • Patent number: 6774249
    Abstract: Improved polymer-immobilized photosensitizer are disclosed as well as methods of preparing and using them. The polymer-immobilized photosensitizers comprise a cross-linked polymer backbone, a plurality of cationic ammonium or phosphonium groups covalently bound to the polymer backbone and an immobilized photosensitizer. The average total number of carbon atoms in the ammonium or phosphonium group is at least four and preferably at least 12. The photosensitizer can be either covalently or ionically bound to the polymer. Polymer-supported photosensitizers of the invention are unexpectedly superior in catalyzing the photosensitized oxidation of compounds containing carbon-carbon double bonds.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: August 10, 2004
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Richard S. Handley, Mark D. Sandison, Randall K. Larkin
  • Publication number: 20040144948
    Abstract: Novel compounds comprising a C—C double bond substituted at one carbon with two oxygen or sulfur atom-containing groups are disclosed. The compounds are useful in methods and compositions for generating chemiluminescence by reaction with a peroxidase enzyme and a peroxide. The chemiluminescence thus produced can be used as a detectable signal in assays for peroxidase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Application
    Filed: January 9, 2004
    Publication date: July 29, 2004
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Publication number: 20040051808
    Abstract: A compact apparatus for digital imaging of luminescent materials is provided. The apparatus can be readily transported by an individual and features a system of collapsible or foldable elements which allow it to be stored in a compact conliguration when not in use. The apparatus is contained within a case which when opened allows the apparatus to be placed into a use configuration by unfolding or otherwise extending the elements of the apparatus. The apparatus is useful for imaging a variety of materials and samples in life science applications.
    Type: Application
    Filed: August 11, 2003
    Publication date: March 18, 2004
    Inventors: Hashem Akhavan-Tafti, Jack Chambers, Richard Handley, Barry Schoenfelner
  • Patent number: 6696569
    Abstract: Novel compounds comprising a C—C double bond substituted at one carbon with two oxygen or sulfur atom-containing groups are disclosed. The compounds are useful in methods and compositions for generating chemiluminescence by reaction with a peroxidase enzyme and a peroxide. The chemiluminescence thus produced can be used as a detectable signal in assays for peroxidase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Grant
    Filed: April 11, 2001
    Date of Patent: February 24, 2004
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Publication number: 20030232405
    Abstract: Methods of producing fluorescence from fluorogenic substrates reactive with a peroxidase enzyme are disclosed. Use of the methods in assays for peroxidase enzymes, peroxidase-labeled analytes are provided. Fluorogenic compounds, compositions and kits for reaction with peroxidase enzymes are described. Two modes of producing fluorescent compounds are described.
    Type: Application
    Filed: June 6, 2002
    Publication date: December 18, 2003
    Inventors: Hashem Akhavan-Tafti, Renuka de Silva, Mark Sandison, Richard Handley
  • Patent number: 6635437
    Abstract: Novel heterocyclic compounds which generate chemiluminescence on reaction with a phosphatase enzyme are provided as well as a process for their preparation and intermediates useful therein. The compounds comprise a nitrogen, oxygen or sulfur-containing heterocyclic ring system bearing an exocyclic carbon—carbon double bond. The double bond is further substituted at the distal carbon with a phosphate group and an oxygen or sulfur atom-containing group. Novel compositions further comprising a cationic aromatic compound (CAC) in addition to the heterocyclic phosphate compound are provided. The addition of the CAC in the composition greatly increases the production of chemiluminescence and provides improved detection sensitivity. Compositions further comprising an anionic surfactant and a non-ionic surfactant provide additional improvements in detection sensitivity.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: October 21, 2003
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Publication number: 20030170762
    Abstract: Novel compounds comprising a C—C double bond substituted at one carbon with two sulfur atom-containing groups are disclosed. The compounds are useful in methods and compositions for generating chemiluminescence rapidly by reaction with a peroxidase enzyme and a peroxide. The chemiluminescence thus produced can be used as a detectable signal in assays for peroxidase enzymes or peroxide-producing enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Application
    Filed: December 20, 2001
    Publication date: September 11, 2003
    Inventors: Hashem Akhavan-Tafti, Renuka de Silva, Wenhua Xie
  • Publication number: 20030170771
    Abstract: Novel compounds comprising a C—C double bond substituted at one carbon with two sulfur atom-containing groups are disclosed. The compounds are useful in methods and compositions for generating chemiluminescence rapidly by reaction with a peroxidase enzyme and a peroxide. The chemiluminescence thus produced can be used as a detectable signal in assays for peroxidase enzymes or peroxide-producing enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Application
    Filed: July 25, 2002
    Publication date: September 11, 2003
    Inventors: Hashem Akhavan-Tafti, Renuka de Silva, Wenhua Xie
  • Publication number: 20030095916
    Abstract: Improved polymer-immobilized photosensitizer are disclosed as well as methods of preparing and using them. The polymer-immobilized photosensitizers comprise a cross-linked polymer backbone, a plurality of cationic ammonium or phosphonium groups covalently bound to the polymer backbone and an immobilized photosensitizer. The average total number of carbon atoms in the ammonium or phosphonium group is at least four and preferably at least 12. The photosensitizer can be either covalently or ionically bound to the polymer. Polymer-supported photosensitizers of the invention are unexpectedly superior in catalyzing the photosensitized oxidation of compounds containing carbon-carbon double bonds.
    Type: Application
    Filed: September 27, 2001
    Publication date: May 22, 2003
    Inventors: Hashem Akhavan-Tafti, Richards S. Handley, Mark D. Sandison, Randall K. Larkin
  • Patent number: 6545102
    Abstract: Improved polymer-immobilized photosensitizer are disclosed as well as methods of preparing and using them. The polymer-immobilized photosensitizers comprise a cross-linked polymer backbone, a plurality of cationic ammonium or phosphonium groups covalently bound to the polymer backbone and an immobilized photosensitizer. The average total number of carbon atoms in the ammonium or phosphonium group is at least four and preferably at least 12. The photosensitizer can be either covalently or ionically bound to the polymer. Polymer-supported photosensitizers of the invention are unexpectedly superior in catalyzing the photosensitized oxidation of compounds containing carbon-carbon double bonds.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: April 8, 2003
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Richard S. Handley, Mark D. Sandison, Randall K. Larkin
  • Publication number: 20030023089
    Abstract: Novel heterocyclic compounds which generate chemiluminescence on reaction with a phosphatase enzyme are provided as well as a process for their preparation and intermediates useful therein. The compounds comprise a nitrogen, oxygen or sulfur-containing heterocyclic ring system bearing an exocyclic carbon-carbon double bond. The double bond is further substituted at the distal carbon with a phosphate group and an oxygen or sulfur atom-containing group.
    Type: Application
    Filed: January 22, 2002
    Publication date: January 30, 2003
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6410732
    Abstract: Synthetic processes and intermediates are disclosed for the preparation of N-arylacridancarboxylic acid derivatives. The derivatives are esters, thioesters, amides and sulfonimides. A key feature of the processes is the preparation of N-aryl substituted intermediates by formation of a bond between the nitrogen atom of the acridan ring and a carbon atom of another aromatic or heteroaromatic ring compound. The arylation reaction is catalyzed by a palladium catalyst. The N-arylacridancarboxylic acid derivatives are useful in methods for producing light and in assays for peroxidase enzymes and enzyme inhibitors and in assays employing enzyme-labeled specific binding pairs.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: June 25, 2002
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Robert A. Eickholt, Richard S. Handley
  • Patent number: 6410751
    Abstract: Stable, enzymatically triggered chemiluminescent 1,2-dioxetanes with improved water solubility and storage stability are provided as well as synthetic processes and intermediates used in their preparation. Dioxetanes further substituted with two or more water-solubilizing groups disposed on the dioxetane structure and an additional fluorine atom or lower alkyl group provide superior performance by eliminating the problem of reagent carryover when used in assays performed on capsule chemistry analytical systems. These dioxetanes display substantially improved stability on storage. Compositions comprising these dioxetanes, a non-polymeric cationic surfactant enhancer and optionally a fluorescer, for providing enhanced chemiluminescence are also provided.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: June 25, 2002
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Renuka DeSilva, Kumar Thakur, Zahra Arghavani
  • Patent number: 6353129
    Abstract: Stable, enzymatically triggered chemiluminescent 1,2-dioxetanes with improved water solubility and storage stability are provided as well as synthetic processes and intermediates used in their preparation. Dioxetanes further substituted with two or more water-solubilizing groups disposed on the dioxetane structure and an additional fluorine atom or lower alkyl group provide superior performance by eliminating the problem of reagent carryover when used in assays performed on capsule chemistry analytical systems. These dioxetanes display substantially improved stability on storage. Compositions comprising these dioxetanes, a non-polymeric cationic surfactant enhancer and optionally a fluorescer, for providing enhanced chemiluminescence are also provided.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: March 5, 2002
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Renuka DeSilva, Kumar Thakur, Zahra Arghavani
  • Publication number: 20020019553
    Abstract: Stable, enzymatically triggered chemiluminescent 1,2-dioxetanes with improved water solubility and storage stability are provided as well as synthetic processes and intermediates used in their preparation. Dioxetanes further substituted with two or more water-solubilizing groups disposed on the dioxetane structure and an additional fluorine atom or lower alkyl group provide superior performance by eliminating the problem of reagent carryover when used in assays performed on capsule chemistry analytical systems. These dioxetanes display substantially improved stability on storage. Compositions comprising these dioxetanes, a non-polymeric cationic surfactant enhancer and optionally a fluorescer, for providing enhanced chemiluminescence are also provided.
    Type: Application
    Filed: April 20, 2001
    Publication date: February 14, 2002
    Inventors: Hashem Akhavan-Tafti, Renuka DeSilva, Kumar Thakur, Zahra Arghavani
  • Publication number: 20010039345
    Abstract: Novel compounds comprising a C—C double bond substituted at one carbon with two oxygen or sulfur atom-containing groups are disclosed. The compounds are useful in methods and compositions for generating chemiluminescence by reaction with a peroxidase enzyme and a peroxide. The chemiluminescence thus produced can be used as a detectable signal in assays for peroxidase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Application
    Filed: April 11, 2001
    Publication date: November 8, 2001
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Publication number: 20010031869
    Abstract: Synthetic processes and intermediates are disclosed for the preparation of N-arylacridancarboxylic acid derivatives. The derivatives are esters, thioesters, amides and sulfonimides. A key feature of the processes is the preparation of N-aryl substituted intermendiates by formation of a bond between the nitrogen atom of the acridan ring and a carbon atom of another aromatic or heteroaromatic ring compound. The arylation reaction is catalyzed by a palladium catalyst. The N-arylacridancarboxylic acid derivatives are useful in methods for producing light and in assays for peroxidase enzymes and enzyme inhibitors and in assays employing enzyme-labeled specific binding pairs.
    Type: Application
    Filed: January 25, 2001
    Publication date: October 18, 2001
    Inventors: Hashem Akhavan-Tafti, Robert A. Eickholt, Richard S. Handley
  • Patent number: 6296787
    Abstract: Novel heterocyclic compounds which generate chemiluminescence on reaction with a phosphatase enzyme are provided as well as a process for their preparation and intermediates useful therein. The compounds comprise a nitrogen, oxygen or sulfur-containing heterocyclic ring system bearing an exocyclic carbon—carbon double bond. The double bond is further substituted at the distal carbon with a phosphate group and an oxygen or sulfur atom-containing group. Novel compositions further comprising a cationic aromatic compound (CAC) in addition to the heterocyclic phosphate compound are provided. The addition of the CAC in the composition greatly increases the production of chemiluminescence and provides improved detection sensitivity. Compositions further comprising an anionic surfactant and a non-ionic surfactant provide additional improvements in detection sensitivity.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: October 2, 2001
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6284899
    Abstract: A chemiluminescent assay method and compositions are described which use a dialkyl-substituted dioxetane which is deprotected to trigger a chemiluminescent reaction. Chemiluminescent 1,2-dioxetane compounds substituted on the dioxetane ring with two nonspirofused alkyl groups which can be triggered by a reagent to generate light are disclosed. Dialkyl-substituted dioxetanes are useful for the detection of triggering agents including enzymes. The enzyme may be present alone or linked to a member of a specific binding pair in an immunoassay, DNA probe assay or other assay where the enzyme is bound to a reporter molecule.
    Type: Grant
    Filed: November 28, 1997
    Date of Patent: September 4, 2001
    Assignees: The Board of Governors of Wayne State University, Lumigen, Inc.
    Inventors: Arthur Paul Schaap, Hashem Akhavan-Tafti