Patents Assigned to Litmus Concepts, Inc.
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Patent number: 6451607Abstract: A control device serving as a source of control reagent for a solid-phase analytical test device is disclosed. The analytical test device analyzes a biological sample for the presence of an analyte such as an enzyme or other chemical species or a particular pH range, and registers the presence or absence of the analyte as a detectable change in an indicator. The control device contains a control reagent that produces the same indicator change and that can be transferred to the analytical test device by a sample implement such as a wet swab. The control reagent is present on the control device as a dry lamina or combination of laminae. A positive control reagent on a control device in accordance with this invention mimics the action of the analyte once it is transferred to the analytical test device, while a negative control reagent on the control device mimics the action of a sample that lacks the analyte.Type: GrantFiled: March 21, 2000Date of Patent: September 17, 2002Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Robert Pena, Terrence J. Andreasen
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Patent number: 6251621Abstract: Methods of assaying for the presence of enzymatically active hydrolases (i.e., hydrolytic enzymes) in a sample or specimen are disclosed. In particular, a method of detecting candidiasis by assaying for the presence of enzymatically active aspartic protease in a sample is provided. In these methods, a sample or specimen is contacted with a solid support. The solid support with which the sample is contacted has a reporter enzyme (i.e., a signal generating enzyme) immobilized thereon. The reporter enzyme is immobilized on the solid support in a manner such that it is released from the solid support upon action of the enzymatically active hydrolase if the enzymatically active hydrolase is, in fact, present in the sample. The sample after having been contacted with the solid support is combined with an indicator. The indicator is any chemical species which is susceptible to a detectable change, usually a change in color, upon action of the reporter enzyme.Type: GrantFiled: March 17, 1995Date of Patent: June 26, 2001Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Aulena Churhuri, Terrence J. Andreasen
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Patent number: 6200817Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable device rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: March 17, 1998Date of Patent: March 13, 2001Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 6113856Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: March 17, 1998Date of Patent: September 5, 2000Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Peter U. Ly, David R. Shockey
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Patent number: 6099801Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable device rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: March 17, 1998Date of Patent: August 8, 2000Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Peter U. Ly, David R. Shockey
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Patent number: 5910447Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: March 18, 1997Date of Patent: June 8, 1999Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Peter U. Ly, David R. Shockey
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Patent number: 5897834Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: March 18, 1997Date of Patent: April 27, 1999Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Peter U. Ly, David R. Shockey
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Patent number: 5660790Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.Type: GrantFiled: August 13, 1996Date of Patent: August 26, 1997Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Peter U. Ly, David R. Shockey
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Patent number: 5585273Abstract: A dry, self-contained test device for assaying for the presence of an enzymatically active hydrolase in a sample is disclosed. The test device combines a reporter enzyme immobilized on a solid support, an indicator, and all other reagents and components necessary to achieve a detectable indication of the presence or absence of the enzymatically active hydrolase in the sample. Preferred devices contain positive and negative controls as well.Type: GrantFiled: November 30, 1994Date of Patent: December 17, 1996Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Aulena Churhuri, Terrence J. Andreasen
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Patent number: 5571684Abstract: The presence of an enzymatically active hydrolase in a fluid sample is detected by contacting the sample with a solid-phase conjugate which is susceptible to cleavage by the hydrolase, and simultaneously or shortly thereafter, contacting the sample with an indicator which undergoes a detectable change upon the action of a reporter group. The reporter group is part of the conjugate and is liberated from it either partly or entirely by the action of the hydrolase. The indicator is susceptible to action by the reporter group only upon decoupling of the reporter group from the remainder of the conjugate, the decoupling occurring either in part or entirely upon action of the hydrolase. Also provided by this invention are various forms of a dry, self-contained test device which contains the conjugate described above plus the indicator and all other reagents and components necessary to achieve a detectable indication of the presence or absence of a catalytically active hydrolase.Type: GrantFiled: January 17, 1995Date of Patent: November 5, 1996Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Terrence J. Andreasen, David R. Shockey
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Patent number: 5416003Abstract: Methods of assaying the presence of enzymatically active hydrolases (i.e., hydrolytic enzymes) in a sample or specimen are disclosed. In particular, a method of detecting candidiasis by assaying for the presence of enzymatically active aspartic protease in a sample is provided. In these methods, a sample or specimen is contacted with a solid support. The solid support with which the sample is contacted has a reporter enzyme (i.e., a signal generating enzyme) immobilized thereon. The reporter enzyme is immobilized on the solid support in a manner such that it is released from the solid support upon action of the enzymatically active hydrolase if the enzymatically active hydrolase is, in fact, present in the sample. The sample after having been contacted with the solid support is combined with an indicator. The indicator is any chemical species which is susceptible to a detectable change, usually a change in color, upon action of the reporter enzyme.Type: GrantFiled: April 14, 1993Date of Patent: May 16, 1995Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Aulena Churhuri, Terrence J. Andreasen
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Patent number: 5268146Abstract: A dry test panel for the testing of samples such as undiluted bodily fluid specimens is disclosed. The panel contains all reagents and components necessary to achieve a visible indication of the presence or absence of a suspect analyte in the sample, and preferred embodiments contain positive and negative controls as well. The device contains an internal chamber into which the specimen is introduced, and which contains all materials necessary for the reactions which produce a color change which is visible on the outer surface of the device. The materials are positioned in the chamber in such a manner that they are activated only when the chamber is filled with the specimen, and the color indicator is concentrated in a thin lamina immediately adjacent to a light-transmitting wall of the device so that a detectable color change occurs in a short period of time to produce a sensitive and yet fast test.Type: GrantFiled: March 25, 1992Date of Patent: December 7, 1993Assignee: Litmus Concepts, Inc.Inventors: Paul J. Lawrence, Marian B. Buccafurni, Leah P. Lawrence
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Patent number: 5068197Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.Type: GrantFiled: May 17, 1990Date of Patent: November 26, 1991Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 5053342Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.Type: GrantFiled: May 7, 1990Date of Patent: October 1, 1991Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4971914Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.Type: GrantFiled: March 28, 1988Date of Patent: November 20, 1990Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4942132Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.Type: GrantFiled: March 28, 1988Date of Patent: July 17, 1990Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4939097Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.Type: GrantFiled: December 24, 1987Date of Patent: July 3, 1990Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4937197Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.Type: GrantFiled: February 11, 1988Date of Patent: June 26, 1990Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4820646Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.Type: GrantFiled: March 28, 1988Date of Patent: April 11, 1989Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence
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Patent number: 4818702Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.Type: GrantFiled: March 31, 1988Date of Patent: April 4, 1989Assignee: Litmus Concepts, Inc.Inventor: Paul J. Lawrence