Test article and method for performing blood coagulation assays
AssigneeAvocet Medical, Inc.
InventorStephen E. Zweig
Life of this patent
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Abstract
A test article for determining coagulation capability in a blood sample comprises a porous membrane having a coagulation initiator and substrate impregnated therein. The pore dimensions and composition of the membrane are selected so that only blood plasma can pass into the interior of the membrane, where coagulation is initiated. The substrate is activated by a component of the coagulation pathway, typically thrombin, and produces a detectable signal upon activation. By utilizing membrane matrix materials which are substantially free from interference with the coagulation pathway, accurate results can be achieved.
Claims27
A test article comprising:
- a single permeable membrane having an application face and an opposite indicator face, said membrane being substantially free from interference with a coagulation pathway, being non-lytic to red blood cells, and having a pore site and distribution which excludes penetration of red blood cells from the application face to the indicator face;
- a coagulation initiator impregnated within the membrane;
- and
- a substrate impregnated within the membrane, which substrate produces a detectable fluorescent signal upon activation by a coagulation pathway proteolytic enzyme;
- wherein the test article is dry and whereby whole blood may be applied to the application face of the membrane and a detectable fluorescent signal is produced on the indicator face as a result of production of the coagulation pathway proteolytic enzyme.
A test article comprising:
- a permeable asymmetric polysulfone membrane having opposite faces;
- thromboplastin impregnated within the membrane;
- and
- a thrombin substrate impregnated within the membrane, said substrate comprising a thrombin-binding peptide cleavably attached to a fluorescent reporter molecule whereby thrombin releases the fluorescent reporter from the substrate;
- whereby whole blood may be applied to one face of the membrane and fluorescence detected on an opposite face as a result of thrombin-mediated cleavage of the thrombin substrate.
A method for determining coagulation capability of a patient, said method comprising:
- applying a whole blood sample to an application face of a permeable membrane, wherein the membrane is substantially free from interference with a coagulation pathway, is non-lytic to red blood cells, and has a pore size and distribution which excludes penetration of red blood cells from the application face to an opposite indicator face, and wherein a coagulation initiator and a substrate which produces a detectable fluorescent signal upon activation by a coagulation pathway proteolytic enzyme are both impregnated within the membrane;
- and
- detecting the fluorescent signal at the indicator face of the membrane, wherein the fluorescent signal results from production of the coagulation pathway proteolytic enzyme within the membrane which had been initiated by interaction of the coagulation initiator with the blood sample.
Dependencies are inferred from the claim text.