Assay test card

Abstract

The present invention relates to the use of surfaces that exhibit different surface energies wherein the difference in surface energies is configured to disrupt capillary laminar flow of a fluid travelling between the two surfaces The invention further relates to the use of such surfaces in assay methods including a device utilising same

1 . An assay device comprising two at least partially opposing surfaces that exhibit different surface energies wherein the difference in surface energies is configured to disrupt capillary laminar flow of a fluid travelling between the two surfaces. 
     
     
         2 . An assay device as claimed in  claim 1  wherein the two at least partially opposing surfaces define at least one fluid flow pathway for transfer of a fluid sample from a first region of the device to a second region of the device. 
     
     
         3 . The assay device of  claim 2  wherein one of the two at least partially opposing surfaces defines an open capillary channel having a cross sectional geometry sufficient to create an open channel configured to form a closed capillary channel with the second of the two at least partially opposing surfaces. 
     
     
         4 . The assay device of  claim 2  wherein spacer elements are configured to hold the two at least partially opposing surfaces some distance apart to create a capillary channel between said surfaces. 
     
     
         5 . An assay device according to  claim 2 , further comprising an application area in fluid communication with the first region of the device for introduction of a fluid sample. 
     
     
         6 . An assay device as claimed in  claim 5  comprising an aperture in one of the two at least partially opposing surfaces for introduction of a fluid sample to the application area. 
     
     
         7 . An assay device as claimed in  claim 5 , further comprising at least one vent port located in the second region of the device. 
     
     
         8 . An assay device as claimed in  claim 5 , further comprising a flow stop junction between the first and second regions of the device configured to halt or pause capillary fluid flow of a fluid travelling between the two surfaces. 
     
     
         9 . An assay device as claimed in  claim 8  wherein the device further comprises a filter membrane disposed between the application area and the at least one fluid flow pathway. 
     
     
         10 . An assay device as claimed in  claim 2 , wherein the fluid flow pathway comprises at least one reagent selected from the group consisting of amphipathic polymers, dyes, probes, enzymes or ligand binding inhibitors. 
     
     
         11 . An assay device as claimed in  claim 10  wherein the fluid flow pathway comprises one or more dyes or probes selected from the group consisting of Amplex Red, K37 and Nile Red. 
     
     
         12 . An assay device as claimed in  claim 10 , wherein the fluid flow path way comprises one or more enzymes selected from the group consisting of Cholesterol esterase, Cholesterol oxidase and Horseradish peroxidise. 
     
     
         13 . An assay device as claimed in  claim 10 , wherein the fluid flow pathway comprises one or more ligand binding inhibitors selected from the group consisting of alkali metal octanoate and octanoic acid. 
     
     
         14 . An assay device as claimed in  claim 10 , further comprising at least one detection zone configured for measurement of the result and/or progress of a reaction between at least a part of a fluid sample and the at least one reagent. 
     
     
         15 . An assay device as claimed in  claim 14  which comprises at least three fluid flow pathways and at least three detection zones wherein, a first flow path is in fluid communication with the application area and a first detection zone, a second fluid flow pathway is in fluid communication with the application area and a second detection zone and a third fluid flow pathway is in fluid communication with the application area and a third detection zone. 
     
     
         16 . An assay device as claimed in  claim 15  wherein the first fluid flow pathway comprises Amplex Red, the second fluid flow pathway comprises K37 and the third fluid flow pathway comprises Nile Red 
     
     
         17 . An assay device as claimed in  claim 16  wherein the first fluid flow pathway further comprises cholesterol esterase, cholesterol oxidase and horseradish peroxidise. 
     
     
         18 . An assay device as claimed in  claim 2 , wherein the fluid flow pathway comprises an amphipathic polymer. 
     
     
         19 . A kit of components comprising at least one assay device as claimed in  claim 1 , and further comprising one or more of (i) a means for sterilising a patient's skin; (ii) skin penetrating means; (iii) gauze; (iv) adhesive plasters; (v) instructional leaflets providing details on use of the device; (vi) disposable gloves and (vii) an assay reader. 
     
     
         20 . A method for the measurement of the level of cholesterol or at least one lipid in a fluid sample, comprising:
 providing an assay device comprising two at least partially opposing surfaces that exhibit different surface energies wherein the difference in surface energies is configured to disrupt capillary laminar flow of a fluid travelling between the two surfaces, and wherein the two at least partially opposing surfaces define at least one fluid flow pathway that comprises at least one reagent selected from the group consisting of amphipathic polymers, dyes, probes, enzymes or ligand binding inhibitors, for transfer of a fluid sample from a first region of the device to a second region of the device, and wherein the assay device further comprises an application area in fluid communication with the first region of the device for introduction of a fluid sample, and at least one detection zone configured for measurement of the result and/or progress of a reaction between at least a part of a fluid sample and the at least one reagent;   introducing a fluid sample into the application area to allow a reaction to occur between the cholesterol or lipid that may be present in the fluid sample and the at least one reagent in the fluid flow pathway; and   detecting the result or the progress of the reaction via the detection zone as a function of the level of the cholesterol or lipid present in the fluid sample.