Patent ID: 8105843
Filing Date: 2012-01-31
Classification: B01L,G01N,Y10S

Abstract:
1. A method for detecting an analyte in a liquid sample and checking the reactivity of the method reagents comprising: (a) isolating a portion of a compressible membrane containing at least a portion of a liquid sample to be analyzed by applying compressive force on top and bottom surfaces of the membrane along a perimeter of an area to be isolated thereby defining a non-compressed area of the membrane centripetal to the compressed perimeter; (b) delivering a pre-determined amount of liquid diluent under pressure to the isolated portion of the membrane to release at least a portion of the liquid sample from the isolated portion of the membrane to provide a diluted sample; (c) contacting the diluted sample with a second porous membrane having a first and second end, wherein the diluted sample flows toward the first and second ends; (d) conducting the diluted sample from one portion of the second porous membrane into a first flow path that provides flow from the second porous membrane upstream to an absorbent pad downstream, wherein the flow path comprises porous membranes and reagents to evaluate reagent reactivity comprising in flow order: (i) a membrane containing mobilizable marker for the class of analytes being detected, (ii) a bridging membrane containing mobilizable binding partners specific to downstream immobilized ligands being used to detect the analytes of interest in the diluted sample, the mobilized binding partners capable of being recognized by the mobilizable marker, (iii) a membrane containing immobilized ligands for the analytes of interest, and (iv) an absorbent pad either in direct fluid communication with the membrane for immobilized ligands or connected thereto via an outflow wick membrane; (e) conducting the diluted sample from different portions of the second porous membrane into a second flow path that provides flow from the second porous membrane upstream to an absorbent pad downstream and comprises porous membranes and reagents to detect specific analytes of interest comprising in flow order: (i) a membrane containing the mobilizable marker, (ii) a bridging membrane connecting the mobilizable marker membrane to a membrane containing immobilized ligands for detecting specific analytes of interest, and (iii) an absorbent pad either in direct fluid communication with the membrane for immobilized ligands or connected to it via an outflow wick membrane; (f) observing the results of migration of the liquid sample through the first flow path comprising observable marker bound to immobilized ligand or ligands for the analyte or analytes of interest, which allows confirmation that the marker was reactive and capable of binding to the class of analytes being detected, that the immobilized ligand or ligands were reactive and capable of binding the specific analytes being detected by the test, and that the mobilizable binding partners specific for the immobilized ligand or ligands were also reactive, thereby indicating that the test is capable of detecting the analytes of interest in the diluted sample; (g) observing the results of migration of the liquid sample through the second flow path comprising observable marker bound to immobilized ligand or ligands for the analyte or analytes of interest, which allows confirmation that analytes of interest are present in the diluted sample, or comprising no observable marker bound to immobilized ligand in the second flow path if no analytes of interest are present in the diluted sample; and (h) observing that no valid interpretation can be reached for the test method if no marker lines are present in immobilized ligand portion of the first flow path.