Patents by Inventor Chitra K. Ratnayake

Chitra K. Ratnayake 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: 9927396
    Abstract: Aspects of the innovations presented herein relate to improved systems that in some embodiments perform capillary electrophoresis (CE) and CE in conjunction with electrospray ionization (ESI) as an input to a mass spectrometry system (MS). Some embodiments use a high voltage isolated CE power supply that is configured to float on the high voltage output of an ESI-MS power supply, with a protective resistance in the ESI-MS path, as well as DC/DC converter isolation and communication system isolation for the isolated CE power supply. Some embodiments additionally use a cartridge assembly integrating separation and conductive fluid capillaries with fluid cooling and protective retractable housings for the capillary end portions and for the ESI output. The protective housing may further be used with an adapter for interfacing with different MS systems.
    Type: Grant
    Filed: October 26, 2012
    Date of Patent: March 27, 2018
    Assignee: DH Technologies Development Pte. Ltd.
    Inventors: Brian D. Peterson, Dale Alan Owens, Peter S. Kotowski, Sunil S. Deliwala, Craig A. Hudson, James H. Reyes, Clive Cheung, Tom Tran, Anna X. Lou, Jane Luo, Jean-Marc Rene Lucien Busnel, Chitra K. Ratnayake
  • Publication number: 20180038829
    Abstract: Aspects of the innovations presented herein relate to improved systems that in some embodiments perform capillary electrophoresis (CE) and CE in conjunction with electrospray ionization (ESI) as an input to a mass spectrometry system (MS). Some embodiments use a high voltage isolated CE power supply that is configured to float on the high voltage output of an ESI-MS power supply, with a protective resistance in the ESI-MS path, as well as DC/DC converter isolation and communication system isolation for the isolated CE power supply. Some embodiments additionally use a cartridge assembly integrating separation and conductive fluid capillaries with fluid cooling and protective retractable housings for the capillary end portions and for the ESI output. The protective housing may further be used with an adapter for interfacing with different MS systems.
    Type: Application
    Filed: October 13, 2017
    Publication date: February 8, 2018
    Inventors: Brian D. Peterson, Dale Alan Owens, Peter S. Kotowski, Sunil S. Deliwala, Craig A. Hudson, James H. Reyes, Clive Cheung, Tom Tran, Anna X. Lou, Jane Luo, Jean-Marc Rene Lucien Busnel, Chitra K. Ratnayake
  • Publication number: 20170335137
    Abstract: Embodiments described herein are directed to, among other things, compositions and methods for coating surfaces, including, but not limited to, coating a surface with a hydrophobic coating using alkoxysilanes. Coated surfaces are also provided.
    Type: Application
    Filed: October 28, 2015
    Publication date: November 23, 2017
    Inventors: Clarence Lew, Chitra K. Ratnayake
  • Publication number: 20140305801
    Abstract: Aspects of the innovations presented herein relate to improved systems that in some embodiments perform capillary electrophoresis (CE) and CE in conjunction with electrospray ionization (ESI) as an input to a mass spectrometry system (MS). Some embodiments use a high voltage isolated CE power supply that is configured to float on the high voltage output of an ESI-MS power supply, with a protective resistance in the ESI-MS path, as well as DC/DC converter isolation and communication system isolation for the isolated CE power supply. Some embodiments additionally use a cartridge assembly integrating separation and conductive fluid capillaries with fluid cooling and protective retractable housings for the capillary end portions and for the ESI output. The protective housing may further be used with an adapter for interfacing with different MS systems.
    Type: Application
    Filed: October 26, 2012
    Publication date: October 16, 2014
    Inventors: Brian D. Peterson, Dale Alan Owens, Peter S. Kotowski, Sunil S. Deliwala, Craig A. Hudson, James H. Reyes, Clive Cheung, Tom Tran, Anna X. Lou, Jian (Jane) Ying Lou, Jean-Marc Rene Lucien Busnel, Chitra K. Ratnayake
  • Publication number: 20110064869
    Abstract: The invention is directed to a capillary tube for electrophoresis that has a positively charged coating on the capillary inner surface that prevents positively charged analytes from adsorbing to the inner capillary surface. The capillary tube has an inner surface that is coated with a first polymer layer having a plurality of polymer groups comprising polyethylene imine, designated herein as (CH2CH2NH)X. The inner surface of the capillary typically has a second polymer layer covalently bonded to the first polymer layer. The invention includes a capillary tube where two or more than two polymer groups are covalently bonded to each other by a cross-linker. Also provided are an electrophoresis system the uses the coated capillary tubes, a method of performing electrophoresis that utilizes the coated capillary tubes, and a process for preparing the coated capillary tubes.
    Type: Application
    Filed: November 19, 2010
    Publication date: March 17, 2011
    Applicant: Beckman Coulter, Inc.
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Patent number: 7857955
    Abstract: The invention is directed to a capillary tube for electrophoresis that has a positively charged coating on the capillary inner surface that prevents positively charged analytes from adsorbing to the inner capillary surface. The capillary tube has an inner surface that is coated with a first polymer layer having a plurality of polymer groups comprising polyethylene imine, designated herein as (CH2CH2NH)x. The inner surface of the capillary typically has a second polymer layer covalently bonded to the first polymer layer. The invention includes a capillary tube where two or more than two polymer groups are covalently bonded to each other by a cross-linker. Also provided are an electrophoresis system the uses the coated capillary tubes, a method of performing electrophoresis that utilizes the coated capillary tubes, and a process for preparing the coated capillary tubes.
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: December 28, 2010
    Assignee: Beckman Coulter, Inc.
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Publication number: 20090314638
    Abstract: This invention relates to improved methods and compositions for conducting Capillary Electrophoresis (CE) to separate molecules on the basis of their respective size or charge.
    Type: Application
    Filed: May 12, 2008
    Publication date: December 24, 2009
    Applicant: Beckman Coulter, Inc.
    Inventors: Yu Liu, M. Parameswara Reddy, Chitra K. Ratnayake, Edward V. Koh
  • Patent number: 7381317
    Abstract: This invention relates to improved methods and compositions for conducting Capillary Electrophoresis (CE) to separate molecules on the basis of their respective size or charge.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: June 3, 2008
    Assignee: Beckman Coulter, Inc.
    Inventors: Yu Liu, M. Parameswara Reddy, Chitra K. Ratnayake, Edward V. Koh
  • Patent number: 6923895
    Abstract: The invention is directed to a capillary tube for electrophoresis that has a positively charged coating on the capillary inner surface that prevents positively charged analytes from adsorbing to the inner capillary surface. The capillary tube has an inner surface that is coated with a first polymer layer having a plurality of polymer groups comprising polyethylene imine, designated herein as (CH2CH2NH)x. The inner surface of the capillary typically has a second polymer layer covalently bonded to the first polymer layer. The invention includes a capillary tube where two or more than two polymer groups are covalently bonded to each other by a cross-linker. Also provided are an electrophoresis system the uses the coated capillary tubes, a method of performing electrophoresis that utilizes the coated capillary tubes, and a process for preparing the coated capillary tubes.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: August 2, 2005
    Assignee: Beckman Coulter, Inc.
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Publication number: 20040050702
    Abstract: This invention relates to improved methods and compositions for conducting Capillary Electrophoresis (CE) to separate molecules on the basis of their respective size or charge.
    Type: Application
    Filed: June 27, 2003
    Publication date: March 18, 2004
    Inventors: Yu Liu, M. Parameswara Reddy, Chitra K. Ratnayake, Edward V. Koh
  • Publication number: 20040045828
    Abstract: The invention is directed to a capillary tube for electrophoresis that has a positively charged coating on the capillary inner surface that prevents positively charged analytes from adsorbing to the inner capillary surface. The capillary tube has an inner surface that is coated with a first polymer layer having a plurality of polymer groups comprising polyethylene imine, designated herein as (CH2CH2NH)x. The inner surface of the capillary typically has a second polymer layer covalently bonded to the first polymer layer. The invention includes a capillary tube where two or more than two polymer groups are covalently bonded to each other by a cross-linker. Also provided are an electrophoresis system the uses the coated capillary tubes, a method of performing electrophoresis that utilizes the coated capillary tubes, and a process for preparing the coated capillary tubes.
    Type: Application
    Filed: September 9, 2002
    Publication date: March 11, 2004
    Inventors: Chitra K. Ratnayake, Isabel C. Flores
  • Patent number: 6465692
    Abstract: Formamide with low conductivity and a neutral or slightly basic pH is provided. Such formamide may be used in a sample loading solution for capillary electrophoretic separation of biomolecular analytes to enhance the efficiency of sample injection into the capillary and the intensity of the signal. Formamide of the present invention may be obtained by first purifying the formamide to a conductivity of below 7 micro mho, and then adjusting the pH of the purified formamide with a base to a range of about pH 6.5 to 7.5. The purification may be carried out by first removing the water from the formamide, and then distilling the dried formamide until the conductivity of formamide is below about 7 micro mho.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: October 15, 2002
    Assignee: Beckman Coulter, Inc.
    Inventors: M. Parameswara Reddy, Chitra K. Ratnayake, Yu Liu, Jirong Gu
  • Patent number: 6294064
    Abstract: Reagents and methods for preparing samples containing both biomolecule analytes and macrobiomolecules for capillary electrophoresis separation are provided. The reagents comprise a branched polymer. When mixed with a sample containing both biomolecule analytes and macrobiomolecules, particularly DNA templates, the branched polymer of the reagent can suppress the entrance of the macrobiomolecules into a capillary electrophoresis tube during electrokinetic injection of the sample into the capillary electrophoresis tube.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: September 25, 2001
    Assignee: Beckman Coulter, Inc.
    Inventors: M. Parameswara Reddy, Tung-Liang Huang, Chitra K. Ratnayake, Daniel A. Keys