Patents by Inventor Anand Natrajan
Anand Natrajan 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).
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Patent number: 9353056Abstract: Zwitterion-containing compounds for the modification of hydrophobic molecules to improve their solubility and/or to lower their non-specific binding as provided. The zwitterion-containing compounds may be suitable for modification of detectable labels such as biotin and fluorescein to improve their solubility. The zwitterion-containing compounds may also be useful for the preparation of conjugates of proteins, peptides and other macromolecules or for crosslinking molecules and/or macromolecules.Type: GrantFiled: May 18, 2011Date of Patent: May 31, 2016Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Sharpe, David Wen, Qingping Jiang
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Publication number: 20160131588Abstract: The present invention relates to methods of enhancing chemiluminescence from a chemiluminescent label comprising contacting a chemiluminescent label with an acid in the presence of a degradable cationic surfactant and hydrogen peroxide followed by the addition of a base. Related kits containing such degradable cationic surfactant are also provided. The degradable cationic surfactant can compress light emission time of the chemiluminescent label to an extent that is comparable to or shorter than conventional surfactants. The degradable cationic surfactant can also increase chemiluminescence of the chemiluminescent label, providing increased light emission output that is comparable to conventional surfactants.Type: ApplicationFiled: May 13, 2014Publication date: May 12, 2016Applicant: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Wen
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Publication number: 20150197491Abstract: A method is provided for N-alkylation of acridine compounds by reduction of acridines to corresponding acridans to improve the reactivity of the acridine nitrogen, and subsequent N-alkylation of the acridans in ionic liquid solvents to provide the corresponding acridinium compounds in high yield. This inventive process improves chemical conversion, and does not require the use of highly toxic alkylating agents, such as 1,3-propane sultone.Type: ApplicationFiled: July 10, 2013Publication date: July 16, 2015Applicant: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Wen
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Publication number: 20140295575Abstract: Hydrophilic, chemiluminescent acridinium compounds containing zwitterions are disclosed. These acridinium compounds, when used as chemiluminescent labels in immunochemistry assays and the like, exhibit decreased non-specific binding to solid phases and provide increased assay sensitivity.Type: ApplicationFiled: June 11, 2014Publication date: October 2, 2014Applicant: SIEMENS HEALTHCARE DIAGNOSTICS INC.Inventors: Anand Natrajan, David Sharpe, Qingping Jiang
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Patent number: 8778624Abstract: Hydrophilic, chemiluminescent acridinium compounds containing zwitterions are disclosed. These acridinium compounds, when used as chemiluminescent labels in immunochemistry assays and the like, exhibit decreased non-specific binding to solid phases and provide increased assay sensitivity.Type: GrantFiled: November 12, 2010Date of Patent: July 15, 2014Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Sharpe, Qingping Jiang
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Publication number: 20130065325Abstract: Zwitterion-containing compounds for the modification of hydrophobic molecules to improve their solubility and/or to lower their non-specific binding as provided. The zwitterion-containing compounds may be suitable for modification of detectable labels such as biotin and fluorescein to improve their solubility. The zwitterion-containing compounds may also be useful for the preparation of conjugates of proteins, peptides and other macromolecules or for crosslinking molecules and/or macromolecules.Type: ApplicationFiled: May 18, 2011Publication date: March 14, 2013Applicant: SIEMENS HEALTHCARE DIAGNOSTICS INC.Inventors: Anand Natrajan, David Sharpe, David Wen, Qingping Jiang
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Patent number: 8293908Abstract: A method is provided for N-alkylation of acridine compounds, typically with a 1,3- propane sultone alkylating reagent, in ionic liquid solvents to provide the corresponding acridinium compounds in high yield.Type: GrantFiled: November 18, 2008Date of Patent: October 23, 2012Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Wen
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Publication number: 20120225497Abstract: Hydrophilic, chemiluminescent acridinium compounds containing zwitterions are disclosed. These acridinium compounds, when used as chemiluminescent labels in immunochemistry assays and the like, exhibit decreased non-specific binding to solid phases and provide increased assay sensitivity.Type: ApplicationFiled: November 12, 2010Publication date: September 6, 2012Applicant: SIEMENS HEALTHCARE DIAGNOSTICS INC.Inventors: Anand Natrajan, David Sharpe, Qingping Jiang
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Patent number: 8119422Abstract: Chemiluminescent acridinium esters are provided which are fast light emitting and hydrolytically stable. The chemiluminescent acridinium esters are useful labels in assays for detecting or quantifying analytes.Type: GrantFiled: October 15, 2007Date of Patent: February 21, 2012Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, Qingping Jiang, David Sharpe
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Patent number: 7875467Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.Type: GrantFiled: November 21, 2007Date of Patent: January 25, 2011Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand A. Natrajan, Todd Sells, Hartmut Schroeder, Guohan Yang, David Sharpe, Qingping Jiang, Hana Lukinsky, Say-Jong Law
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Publication number: 20100256380Abstract: A method is provided for N-alkylation of acridine compounds, typically with a 1,3-propane sultone alkylating reagent, in ionic liquid solvents to provide the corresponding acridinium compounds in high yield.Type: ApplicationFiled: November 18, 2008Publication date: October 7, 2010Applicant: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Wen
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Patent number: 7785904Abstract: The present invention relates to hydrophilic, high quantum yield acridinium compounds. It has been discovered that the placement of electron-donating groups in the acridinium ring system increases the amount of light that is emitted by the corresponding acridinium compound when its chemiluminescence is triggered by alkaline peroxide. More specifically, it has been found that the placement of one or two hydrophilic, alkoxy groups at the C-2 and/or C-7 position of the acridinium ring system of acridinium compounds increases their quantum yield and enhances the aqueous solubility of these compounds. The present hydrophilic, high quantum yield, acridinium compounds are useful chemiluminescent labels for improving the sensitivity of immunoassays.Type: GrantFiled: June 19, 2007Date of Patent: August 31, 2010Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, James Costello
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Publication number: 20100099077Abstract: Chemiluminescent acridinium esters are provided which are fast light emitting and hydrolytically stable. The chemiluminescent acridinium esters are useful labels in assays for detecting or quantifying analytes.Type: ApplicationFiled: October 15, 2007Publication date: April 22, 2010Applicant: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, Qingping Jiang, David Sharpe
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Publication number: 20090318627Abstract: Acridinium-functionalized solid-phase supports and methods for making acridinium-functionalized solid-phase supports are disclosed. The acridinium-functionalized solid-phase supports comprise a solid phase support linked to a chemiluminescent substituted acridinium compound through a linker group covalently attached to the nitrogen atom of the acridinium nucleus and the solid phase support as exemplified in FIG. 1.Type: ApplicationFiled: February 6, 2007Publication date: December 24, 2009Applicant: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, David Sharpe, Jim Costello, Qingping Jiang
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Patent number: 7611909Abstract: A method for the detection or quantitation of unlabeled target analyte in a biological sample, the method comprising labeling a target analyte for a biological sample suspected of containing unlabeled target analyte with an acridinium compound to form a labeled target analyte and providing the labeled target analyte to the biological sample, or providing the labeled target analyte to the biological sample, wherein the acridinium compound comprises an acridinium nucleus having an electron-donating substituent directly attached to the acridinium nucleus, with the electron-donating substituent attached at the C2 position. Chemiluminescent acridinium compounds useful in the method have emission maxima close to or in the near infrared (NIR) region (>590 nm).Type: GrantFiled: November 4, 2005Date of Patent: November 3, 2009Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, Say-Jong Law
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Publication number: 20090029349Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.Type: ApplicationFiled: November 21, 2007Publication date: January 29, 2009Applicant: Siemens Medical Solutions DiagnosticsInventors: Anand A. Natrajan, Todd Sells, Hartmut Schroeder, Guohan Yang, David Sharpe, Qingping Jiang, Hana Lukinsky, Say-Jong Law
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Publication number: 20080305557Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.Type: ApplicationFiled: November 21, 2007Publication date: December 11, 2008Applicant: Siemens Medical Solutions DiagnosticsInventors: Anand Natrajan, Todd Sells, Hartmut Schroeder, Guohan Yang, David Sharpe, Qingping Jiang, Hana Lukinsky, Say-Jong Law
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Patent number: 7459284Abstract: A chemiluminescent substrate of a hydrolytic enzyme having the following general Formula I is disclosed, as follows: Lumi-M-P??Formula I where “Lumi” is a chemiluminescent moiety capable of producing light (a) by itself, (b) with MP attached and (c) with M attached. Examples of Lumi include chemiluminescent acridinium compounds, benzacridinium compounds, quinolinium compounds, isoquinolinium compounds, phenanthridinium compounds, and lucigenin compounds, spiroacridan compounds, luminol compounds and isoluminol compounds. M is a multivalent heteroatom having at least one lone pair of electrons selected from oxygen, nitrogen and sulfur, directly attached to the light emitting moiety of Lumi at one end and to P at the other end. P is a group that can be readily removed by hydrolytic enzymes. An enzymatic reaction utilizing the above compound is the following: where HE is a hydrolytic enzyme. Lumi-M is a chemiluminescent product having physical and/or chemical properties different from those of Lumi-M-P.Type: GrantFiled: June 5, 2006Date of Patent: December 2, 2008Assignee: Siemens Healthcare Diagnostics Inc.Inventors: Qingping Jiang, Anand Natrajan, David Sharpe, Wen-Jee Wong, Say-Jong Law
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Publication number: 20080014660Abstract: The present invention relates to hydrophilic, high quantum yield acridinium compounds. It has been discovered that the placement of electron-donating groups in the acridinium ring system increases the amount of light that is emitted by the corresponding acridinium compound when its chemiluminescence is triggered by alkaline peroxide. More specifically, it has been found that the placement of one or two hydrophilic, alkoxy groups at the C-2 and/or C-7 position of the acridinium ring system of acridinium compounds increases their quantum yield and enhances the aqueous solubility of these compounds. The present hydrophilic, high quantum yield, acridinium compounds are useful chemiluminescent labels for improving the sensitivity of immunoassays.Type: ApplicationFiled: June 19, 2007Publication date: January 17, 2008Inventors: Anand Natrajan, Qingping Jiang, David Sharpe, James Costello
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Patent number: 7319041Abstract: Chemiluminescent acridinium compounds are used in homogeneous assays to determine the concentration of an analyte in a sample without strong acid or strong base treatment. The chemiluminescent acridinium compounds include acridinium esters with electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus to inhibit pseudo-base formation, or acridinium sulfonamides with or without electron donating functional groups at the C2 and/or C7 position on the acridinium nucleus.Type: GrantFiled: September 27, 2002Date of Patent: January 15, 2008Assignee: Siemens Medical Solutions DiagnosticInventors: Anand Natrajan, Todd Sells, Hartmut Schroeder, Guohan Yang, David Sharpe, Qingping Jiang, Hana Lukinsky, Say-Jong Law