Patents by Inventor Subhakar Dey

Subhakar Dey 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: 20190212337
    Abstract: Systems and methods are provided for microbial identification using cleavable tags. Control information is sent to a mass spectrometer to fragment one or more nucleic acid primers labeled with a first tag and monitor for an intensity of the first tag in a mass spectrometry (MS) method. An ion source provides a beam of ions from a polymerase chain reaction amplified sample that includes one or more nucleic acid primers labeled with the first tag. The first tag binds to one or more nucleic acid primers of a known microbe and is cleaved from the nucleic acid primers during the MS method. The mass spectrometer receives the beam of ions and is adapted to perform the MS method on the beam of ions. If the intensity of the first tag received from the mass spectrometer exceeds a threshold value, the known microbe is identified in the sample.
    Type: Application
    Filed: March 19, 2019
    Publication date: July 11, 2019
    Inventors: Subhasish Purkayastha, Subhakar Dey
  • Patent number: 10281468
    Abstract: Systems and methods are provided for microbial identification using cleavable tags. Control information is sent to a mass spectrometer to select a peptide labeled with a first tag of a known microbe, fragment the labeled peptide of the known microbe, and monitor for an intensity of the first tag in an MRM method using a processor. An ion source provides a beam of ions from a sample that includes peptides labeled with the first tag. The first tag binds to a peptide of a known microbe and is cleaved from the peptide of the known microbe during mass spectrometry. The mass spectrometer receives the beam of ions and is adapted to perform the MRM method on the beam of ions. If the intensity of the first tag received from the mass spectrometer exceeds a threshold value, the known microbe is identified in the sample using the processor.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: May 7, 2019
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhasish Purkayastha, Subhakar Dey
  • Patent number: 10094809
    Abstract: Labeling reagents, sets of labeling reagents, and labeling techniques are provided for the relative quantitation, absolute quantitation, or both, of ketone or aldehyde compounds including, but not limited to, analytes comprising steroids or ketosteroids and includes testosterone. The analytes can be medical or pharmaceutical compounds in biological samples. Methods for labeling, analyzing, and quantifying ketone or aldehyde compounds are also disclosed as are methods that also use mass spectrometry.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: October 9, 2018
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Sasi Pillai, Brian L. Williamson, Subhasish Purkayastha, Michal Weinstock
  • Patent number: 9964552
    Abstract: A method is described for mass spectrometric analysis, detection and quantification of catecholamines. The methods can comprise reacting the catecholamines with a 4-aminoantipyrine reagent and detecting and/or quantifying the adduct produced by the reaction. The methods can also allow for multiplexing. Compounds formed by the reactions are also provided.
    Type: Grant
    Filed: October 22, 2014
    Date of Patent: May 8, 2018
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Subhasish Purkayastha
  • Patent number: 9874575
    Abstract: A method is described for mass spectrometric analysis of a sample comprising phenolic OH, such as a steroid comprising a phenolic OH, using a quaternary amino oxy Cookson (QAOC) reagent. The QAOC reagent can improve ionization and fragmentation properties of phenolic OH samples, which can thereby improve quantitation and identification. The method can include derivatizing the phenolic OH sample with the QAOC reagent to create an adduct and analyzing the adduct using mass spectrometry. Derivatization of the sample can be a one-step reaction where the QAOC reagent comprises an aminooxy MS tag or can be a multi-step reaction, where the adduct is formed by the reaction of carbonyl substituted PTAD based reagent and the sample followed by combination with an aminooxy MS tag. The sample can also be enriched prior to reacting it with the reagent. The method can also allow for multiplexing.
    Type: Grant
    Filed: January 16, 2013
    Date of Patent: January 23, 2018
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Subhasish Purkayastha
  • Publication number: 20170115258
    Abstract: Labeling reagents, sets of labeling reagents, and labeling techniques are provided for the relative quantitation, absolute quantitation, or both, of ketone or aldehyde compounds including, but not limited to, analytes comprising steroids or ketosteroids and includes testosterone. The analytes can be medical or pharmaceutical compounds in biological samples. Methods for labeling, analyzing, and quantifying ketone or aldehyde compounds are also disclosed as are methods that also use mass spectrometry.
    Type: Application
    Filed: October 31, 2016
    Publication date: April 27, 2017
    Inventors: Subhakar Dey, Sasi Pillai, Brian L. Williamson, Subhasish Purkayastha, Michal Weinstock
  • Publication number: 20170052180
    Abstract: Systems and methods are provided for microbial identification using cleavable tags. Control information is sent to a mass spectrometer to select a peptide labeled with a first tag of a known microbe, fragment the labeled peptide of the known microbe, and monitor for an intensity of the first tag in an MRM method using a processor. An ion source provides a beam of ions from a sample that includes peptides labeled with the first tag. The first tag binds to a peptide of a known microbe and is cleaved from the peptide of the known microbe during mass spectrometry. The mass spectrometer receives the beam of ions and is adapted to perform the MRM method on the beam of ions. If the intensity of the first tag received from the mass spectrometer exceeds a threshold value, the known microbe is identified in the sample using the processor.
    Type: Application
    Filed: February 25, 2015
    Publication date: February 23, 2017
    Inventors: Subhasish Purkayastha, Subhakar Dey
  • Patent number: 9500622
    Abstract: Labeling reagents, sets of labeling reagents, and labeling techniques are provided for the relative quantitation, absolute quantitation, or both, of ketone or aldehyde compounds including, but not limited to, analytes comprising steroids or ketosteroids. The analytes can be medical or pharmaceutical compounds in biological samples. Methods for labeling, analyzing, and quantifying ketone or aldehyde compounds are also disclosed as are methods that also use mass spectrometry.
    Type: Grant
    Filed: May 20, 2013
    Date of Patent: November 22, 2016
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Sasi Pillal, Brian L. Williamson, Subhasish Purkayastha, Michal Weinstock
  • Publication number: 20160305969
    Abstract: A method is described for mass spectrometric analysis, detection and quantification of catecholamines. The methods can comprise reacting the catecholamines with a 4-aminoantippyrine reagent and detecting and/or quantifying the adduct produced by the reaction. The methods can also allow for multiplexing. Compounds formed by the reactions are also provided.
    Type: Application
    Filed: October 22, 2014
    Publication date: October 20, 2016
    Applicant: DH TECHNOLOGIES DEVELOPMENT PTE. LTD.
    Inventors: Subhakar Dey, Subhasish Purkayastha
  • Patent number: 9188596
    Abstract: Quantification of vitamin D2, vitamin D3, and the monohydroxy and diihydroxy metabolites of vitamin D2 and vitamin D3, can comprise labeling analytes with mass spectrometry (MS) tagging reagents and performing LC-MSMS analysis of the labeled analytes. The labeled analytes can include a labeled standard and can have distinct retention times on a reversed phase column, as well as distinct masses. Under high energy collisions, reporter groups can be generated. The intensity or the peak area detected for each reporter group can be used for quantitation. In some embodiments, a one-step tagging reagent is used that is a dienophile-containing, labeled m Diels Alder reagent.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: November 17, 2015
    Assignee: DH Technologies Development Pte. Ltd
    Inventors: Subhakar Dey, Sasi Pillal, Brian L. Williamson, Subhasish Purkayastha
  • Patent number: 8975404
    Abstract: Provided herein are labeling reagents for analyte determination in a sample, and methods of manufacturing the labeling reagents. By way of non-limiting example, analytes may include one or more of peptides, proteins, nucleic acid molecules, carbohydrates, lipids, steroids and/or small molecules. Also provided are labeled analytes themselves after one or more labeling reagents binds to an analyte. Analytes may be labeled for determination of the analyte by mass analysis, such as by mass spectrometry. Further provided are compounds that may be used in making the labeling reagents and labeled analytes, such as reporter group compounds. Also provided are kits that include at least one labeling reagent, and may further include or more other reagents, containers, enzymes, buffers, a labeled analyte (e.g., as a standard) and/or instructions. Further examples are also possible.
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: March 10, 2015
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Sasi K. Pillai, Subhakar Dey, Subhasish Purkayastha, Darryl J. C. Pappin
  • Publication number: 20150051111
    Abstract: A method is described for mass spectrometric analysis of a sample comprising phenolic OH, such as a steroid comprising a phenolic OH, using a quaternary amino oxy Cookson (QAOC) reagent. The QAOC reagent can improve ionization and fragmentation properties of phenolic OH samples, which can thereby improve quantitation and identification. The method can include derivatizing the phenolic OH sample with the QAOC reagent to create an adduct and analyzing the adduct using mass spectrometry. Derivatization of the sample can be a one-step reaction where the QAOC reagent comprises an aminooxy MS tag or can be a multi-step reaction, where the adduct is formed by the reaction of carbonyl substituted PTAD based reagent and the sample followed by combination with an aminooxy MS tag. The sample can also be enriched prior to reacting it with the reagent. The method can also allow for multiplexing.
    Type: Application
    Filed: January 16, 2013
    Publication date: February 19, 2015
    Inventors: Subhakar Dey, Subhasish Purkayastha
  • Publication number: 20140349885
    Abstract: A method, a labeling reagent, sets of labeling reagents, and labeling techniques are provided for the relative quantitation, absolute quantitation, or both, of ketone or aldehyde compounds including, but not limited to, analytes comprising steroids or ketosteroids. The analytes can be medical or pharmaceutical compounds in biological matrices. Methods for labeling, analyzing, and quantifying ketone or aldehyde compounds are also disclosed as are methods that also use mass spectrometry.
    Type: Application
    Filed: December 6, 2012
    Publication date: November 27, 2014
    Inventors: Subhakar Dey, Subhasish Purkayastha
  • Patent number: 8853133
    Abstract: This invention pertains to methods, mixtures, kits and compositions pertaining to analyte determination and/or quantification by mass spectrometry using compounds comprising a reporter moiety and a non-encoded detectable label. The compounds can be used in sets for the analysis of mixtures of labeled analytes.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: October 7, 2014
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhasish Purkayastha, Subhakar Dey
  • Publication number: 20140127825
    Abstract: Quantification of vitamin D2, vitamin D3, and the monohydroxy and diihydroxy metabolites of vitamin D2 and vitamin D3, can comprise labeling analytes with mass spectrometry (MS) tagging reagents and performing LC-MSMS analysis of the labeled analytes. The labeled analytes can include a labeled standard and can have distinct retention times on a reversed phase column, as well as distinct masses. Under high energy collisions, reporter groups can be generated. The intensity or the peak area detected for each reporter group can be used for quantitation. In some embodiments, a one-step tagging reagent is used that is a dienophile-containing, labeled m Diels Alder reagent.
    Type: Application
    Filed: December 12, 2013
    Publication date: May 8, 2014
    Applicant: DH TECHNOLOGIES DEVELOPMENT PTE. LTD.
    Inventors: Subhakar Dey, Sasi Pillal, Brian L. Williamson, Subhasish Purkayastha
  • Publication number: 20140004616
    Abstract: Labeling reagents, sets of labeling reagents, and labeling techniques are provided for the relative quantitation, absolute quantitation, or both, of ketone or aldehyde compounds including, but not limited to, analytes comprising steroids or ketosteroids. The analytes can be medical or pharmaceutical compounds in biological samples. Methods for labeling, analyzing, and quantifying ketone or aldehyde compounds are also disclosed as are methods that also use mass spectrometry.
    Type: Application
    Filed: May 20, 2013
    Publication date: January 2, 2014
    Applicant: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Sasi Pillal, Brian L. Williamson, Subhasish Purkayastha, Michal Weinstock
  • Patent number: 8617898
    Abstract: Quantification of vitamin D2, vitamin D3, and the monohydroxy and diihydroxy metabolites of vitamin D2 and vitamin D3, can comprise labeling analytes with mass spectrometry (MS) tagging reagents and performing LC-MSMS analysis of the labeled analytes. The labeled analytes can include a labeled standard and can have distinct retention times on a reversed phase column, as well as distinct masses. Under high energy collisions, reporter groups can be generated. The intensity or the peak area detected for each reporter group can be used for quantitation. In some embodiments, a one-step tagging reagent is used that is a dienophile-containing, labeled Diels Alder reagent.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: December 31, 2013
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Sasi K. Pillai, Brian Williamson, Subhasish Purkayastha
  • Patent number: 8569304
    Abstract: In some embodiments, this invention pertains to active esters of N-substituted piperazine acetic acid, including isotopically enriched versions thereof. In some embodiments, this invention pertains to methods for the preparation of active esters of N-substituted piperazine acetic acid, including isotopically enriched versions thereof.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: October 29, 2013
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhakar Dey, Darryl J. C. Pappin, Subhasish Purkayastha, Sasi Pillai, James M. Coull
  • Patent number: 8501498
    Abstract: This invention pertains to methods, mixtures, kits and/or compositions for the determination of analytes by mass analysis using unique labeling reagents or sets of unique labeling reagents. The labeling reagents can be isomeric or isobaric and can be used to produce mixtures suitable for multiplex analysis of the labeled analytes.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: August 6, 2013
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Xiongwei Yan, Pau-Miau Yuan, Sylvia W. Yuen, Kuo-Liang Hsi, Joe Y. Lam, Krishna G. Upadhya, Subhakar Dey, Darryl J. C. Pappin, Sasi Pillai, Helena Huang, Subhasish Purkayastha
  • Patent number: 8492163
    Abstract: This invention pertains to methods, mixtures, kits and compositions pertaining to analyte determination by mass spectrometry using labeling reagents that comprise a nucleophilic reactive group that reacts with a functional group of an analyte to produce a labeled analyte. The labeling reagents can be used as isobaric sets, mass differential labeling sets or in a combination of isobaric and mass differential labeling sets.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: July 23, 2013
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Subhasish Purkayastha, Subhakar Dey, Scott B. Daniels