Dry test strip comprising a dextran barrier for excluding erythrocytes
AssigneeGenesis Labs, Inc.
InventorCatherine B. Maddox
Life of this patent
Estimating the term…
Abstract
A dry test strip for the detection of an analyte in a test fluid is disclosed. The test strip comprises a porous detection zone containing a reactant system that can generate a signal in the presence of an analyte. The detection zone further comprises dextran as a barrier to prevent penetration of RBC's into the detection zone.
Claims21
A dry test strip for detection of an analyte in a test fluid comprising:
- (a) a porous detection zone having a test fluid application site physically separate from a visualization site containing a signal generating system that produces a signal in the presence of the analyte, wherein the detection zone pores are about 0.04 to 1 micron;
- and
- (b) dextran, having a molecular weight of about 10,000 to 50,000 dispersed in the detection zone at a concentration effective to prevent penetration of red blood cells through the detection zone to the visualization site;
- wherein any red blood cells present in the test fluid interact with the dextran adjacent the test fluid application site to prevent their penetration through the detection zone to the visualization site thereby essentially eliminating red blood cell interference with the signal generation.
A dry test strip for detection of an analyte, in a test fluid containing red blood cells which comprises a carrier strip having a porous detection zone having pores of about 0.04 to 1 micron and containing a signal generating system that produces a signal in the presence of the analyte, said detection zone having a discrete barrier layer on the surface of the detection zone comprising a sufficient amount of dextran having a molecular weight of about 10,000 to 50,000 to prevent the penetration through the porous detection zone and interference with the signal generation system by the red blood cells.
A method for detecting an analyte in a test fluid which method comprises:
- (a) applying the test fluid to a dry test strip comprising
- a porous detection zone having pores of about 0.04 to 1 micron and a test fluid application site physically separate from a visualization site containing:
- (i) a signal generating system that produces a signal in the presence of the analyte;
- and
- (ii) dextran having a molecular weight of about 10,000 to 50,000, dispersed through the detection zone at a concentration effective to prevent penetration of any red blood cells present in the fluid through the detection zone;
- and
- (b) detecting the concentration of the analyte;
- wherein any red blood cells present in the test fluid interact with the dextran adjacent the application site to prevent their penetration through the detection zone to the visualization site thereby essentially eliminating red blood cell interference with the signal generation.
Dependencies are inferred from the claim text.