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).

  • Patent number: 6270695
    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: July 21, 1999
    Date of Patent: August 7, 2001
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6245928
    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: February 17, 2000
    Date of Patent: June 12, 2001
    Assignee: Lumigen, Inc.
    Inventors: Zahra Arghavani, Hashem Akhavan-Tafti, Renuka DeSilva, Kumar Thakur
  • Patent number: 6218137
    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: March 31, 2000
    Date of Patent: April 17, 2001
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6139782
    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: July 21, 1999
    Date of Patent: October 31, 2000
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6126870
    Abstract: Chemiluminescent labeling compounds and chemiluminescent labeled conjugates are provided. The compounds comprise an acridan ring bearing an exocyclic double bond and further contain a labeling substituent which permits attachement to compounds of interest. The novel chemiluminescent compounds and labeled conjugates generated chemiluminescence rapidly after undergoing a reaction with an acid, an oxidant and a base. The compounds and conjugates are useful in assays of an analyte in a sample and in assays employing labeled specific binding pairs.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: October 3, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6090571
    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: July 21, 1999
    Date of Patent: July 18, 2000
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6068979
    Abstract: A method for sequential chemiluminescent detection of two differently labeled analytes on a single blot is described. In the method, a uniquely labeled DNA is detected with a horseradish peroxidase (HRP) substrate followed by the detection of another uniquely labeled DNA with a second different enzyme substrate which also inhibits the chemiluminescence generated by HRP. The sequential detection method described herein eliminates the need to strip and reprobe Southern, Northern and Western blots. Potential applications of this method include forensic DNA fingerprinting where more than one probe is used for probing a Southern blot, multiplex DNA sequencing of more than one template, detection of gene rearrangements, mutations and gene linkage.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: May 30, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6045991
    Abstract: Compounds which generate red chemiluminescence on reaction with a phosphatase enzyme are provided as well as intermediates useful for their preparation. The chemiluminescent compounds comprise a luciferin ring system and an exocyclic enol phosphate group where the position on the luciferin ring system adjacent to the double bond is disubstituted. The chemiluminescent compounds are useful alone or within compositions containing a cationic aromatic compound in methods for producing chemiluminescence. The chemiluminescent reactions can be applied in assays for phosphatase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: April 4, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6045727
    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 heterocyclicring 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: August 13, 1997
    Date of Patent: April 4, 2000
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Renuka DeSilva
  • Patent number: 6036892
    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: July 7, 1998
    Date of Patent: March 14, 2000
    Assignee: Lumigen, Inc.
    Inventors: Zahra Arghavani, Hashem Akhavan-Tafti, Renuka DeSilva, Kumar Thakur
  • Patent number: 6020138
    Abstract: Methods of synthesizing polynucleotides are disclosed involving the simultaneous ligation of a set of oligomer 5'-phosphates onto a template-bound primer. The set of these oligomers can be preselected to contain oligomers which are complementary to the template strand or the oligomers can be supplied as a library and allowed to self select. The synthesis by ligation can proceed unidirectionally or bidirectionally from the primer and can be used to synthesize both strands simultaneously by the use of two primers. The ligation is preferably performed with a ligase enzyme. The methods of synthesis are useful in a variety of applications, including cloning, amplification, labeling, diagnostic assays, mutation analysis and screening, gene expression monitoring and sequence analysis.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: February 1, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6017769
    Abstract: Methods of generating chemiluminescence rapidly without the use of enzymes are provided. The methods utilize chemiluminescent compounds comprising an acridan ring bearing an exocyclic double bond in a reaction with an acid, an oxidant and a base. The chemiluminescent methods are useful in assays to detect the amount of an analyte in a sample. The chemiluminescent compounds may be supplied as a label on an analyte or a specific binding partner or may be encapsulated within a liposome or latex particle.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: January 25, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6013456
    Abstract: Methods of synthesizing polynucleotides are disclosed involving the simultaneous ligation of a set of oligomer 5'-phosphates onto a template-bound primer. The set of these oligomers can be preselected to contain oligomers which are complementary to the template strand or the oligomers can be supplied as a library and allowed to self select. The synthesis by ligation can proceed unidirectionally or bidirectionally from the primer and can be used to synthesize both strands simultaneously by the use of two primers. The ligation is preferably performed with a ligase enzyme. The methods of synthesis are useful in a variety of applications, including cloning, amplification, labeling, diagnostic assays, mutation analysis and screening, gene expression monitoring and sequence analysis.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: January 11, 2000
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 6001614
    Abstract: Methods of synthesizing polynucleotides are disclosed involving the simultaneous ligation of a set of oligomer 5'-phosphates onto a template-bound primer. The set of these oligomers can be preselected to contain oligomers which are complementary to the template strand or the oligomers can be supplied as a library and allowed to self select. The synthesis by ligation can proceed unidirectionally or bidirectionally from the primer and can be used to synthesize both strands simultaneously by the use of two primers. The ligation is preferably performed with a ligase enzyme. The methods of synthesis are useful in a variety of applications, including cloning, amplification, labeling, diagnostic assays, mutation analysis and screening, gene expression monitoring and sequence analysis.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: December 14, 1999
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 5998175
    Abstract: Methods of synthesizing polynucleotides are disclosed involving the simultaneous ligation of a set of oligomer 5'-phosphates onto a template-bound primer. The set of these oligomers can be preselected to contain oligomers which are complementary to the template strand or the oligomers can be supplied as a library and allowed to self select. The synthesis by ligation can proceed unidirectionally or bidirectionally from the primer and can be used to synthesize both strands simultaneously by the use of two primers. The ligation is preferably performed with a ligase enzyme. The methods of synthesis are useful in a variety of applications, including cloning, amplification, labeling, diagnostic assays, mutation analysis and screening, gene expression monitoring and sequence analysis.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: December 7, 1999
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 5965736
    Abstract: Compounds which generate red chemiluminescence on reaction with a phosphatase enzyme are provided as well as intermediates useful for their preparation. The chemiluminescent compounds comprise a luciferin ring system and an exocyclic enol phosphate group where the position on the luciferin ring system adjacent to the double bond is disubstituted. The chemiluminescent compounds are useful alone or within compositions containing a cationic aromatic compound in methods for producing chemiluminescence. The chemiluminescent reactions can be applied in assays for phosphatase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Grant
    Filed: December 9, 1998
    Date of Patent: October 12, 1999
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 5936101
    Abstract: A process for producing a stable triggerable dioxetane comprising;(a) reacting a vinyl sulfide compound containing a sulfur-substituent SR.sub.4, wherein R.sub.4 is an organic group containing 1 to 20 carbon atoms and optionally heteroatoms, with oxygen and light in the presence of a photosensitizer to form an intermediate sulfur-substituted dioxetane compound; and(b) reacting the sulfur-substituted dioxetane compound with an electrophilic compound E--Y and a hydroxylic compound R.sub.5 OH selected from the group consisting of alcohols, phenols and carboxylic acids or their salts and containing an OR.sub.5 group to replace the SR.sub.4 group of the dioxetane with the OR.sub.5 group.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: August 10, 1999
    Assignee: Lumigen, Inc.
    Inventors: Hashem Akhavan-Tafti, Zahra Arghavani, Robert A. Eickholt
  • Patent number: 5922558
    Abstract: Methods and compositions for generating chemiluminescence on reaction with a peroxidase enzyme are provided as well as compounds to be used in the methods and compositions. The compounds have a C--C double bond substituted at one carbon with two oxygen or sulfur atom-containing groups. The compositions contain the double bond-containing compound and a peroxide in an aqueous solution. Additional components which can be included in the compositions are peroxidase activity enhancers, nonionic surfactants or cationic surfactants to improve detection sensitivity of the peroxidase. The chemiluminescent methods and compositions are useful in assays for peroxidase enzymes and in assays employing enzyme-labeled specific binding pairs.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: July 13, 1999
    Assignee: Lumigen, Inc.
    Inventor: Hashem Akhavan-Tafti
  • Patent number: 5892064
    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 26, 1997
    Date of Patent: April 6, 1999
    Assignee: Lumigen, Inc.
    Inventors: Arthur Paul Schaap, Hashem Akhavan-Tafti
  • Patent number: 5886238
    Abstract: Alkene precursors for preparing dialkyl-substituted dioxetanes. The dioxetanes are useful for the detection of triggering agents including enzymes.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: March 23, 1999
    Assignees: Lumigen, Inc., The Board of Governors of Wayne State University
    Inventors: Arthur Paul Schaap, Hashem Akhavan-Tafti