Device for diluting a fluid and detecting analytes within a diluted fluid

Abstract

The present invention provides a device for processing, sampling, and diluting a fluid and for detecting an analyte within the processed, sampled, and diluted fluid. In the device for processing, sampling, and diluting a fluid, an amount of fluid to be processed, sampled, and diluted is accepted by a compressible porous membrane; a portion of the membrane saturated with the fluid is isolated thereby defining a predetermined sample volume of fluid; and the predetermined fluid volume sample is then released from the isolated membrane with a specified quantity of a fluid diluent to provide a diluted fluid sample. Analytes within the diluted fluid sample are detected by test strips in fluid contact with the diluted fluid sample.

1 . A device for processing and sampling a fluid, comprising:
 (a) a compressible porous membrane for receiving a first fluid, wherein the membrane allows for migration of the first fluid from the point of application at a position other than a portion of the membrane to be isolated and allows sufficient migration to saturate the portion of the membrane to be isolated;   (b) first and second members adjacent opposing major surfaces of the membrane, wherein the first and second members are engageable to apply compressive force on top and bottom surfaces of the membrane along the perimeter of the area to be isolated, thereby defining a non-compressed area of saturated membrane centripetal to the compressed perimeter;   (c) a port adapted to receive delivery of a second fluid, wherein the port is further adapted to deliver the second fluid under pressure to the isolated portion of the membrane to force the removal of the first fluid from the isolated portion of the membrane; and   (d) a receptacle in fluid communication with the isolated membrane for receiving the first fluid from the isolated portion of the membrane.   
     
     
         2 . A device for diluting a liquid, comprising:
 (a) a compressible porous membrane for receiving a liquid, wherein the membrane allows for migration of the liquid from the point of application at a position other than a portion of the membrane to be isolated and allows sufficient migration to saturate the portion of the membrane to be isolated;   (b) first and second members adjacent opposing major surfaces of the membrane, wherein the first and second members are engageable to apply compressive force on top and bottom surfaces of the membrane along the perimeter of the area to be isolated, thereby defining a non-compressed area of saturated membrane centripetal to the compressed perimeter;   (c) a port adapted to receive delivery of a diluent, wherein the port is further adapted to deliver the diluent under pressure to the isolated portion of the membrane saturated with the liquid sample and to force the removal of the liquid sample from the isolated portion of the membrane; and   (d) a receptacle in fluid communication with the isolated membrane for receiving the diluted liquid sample from the isolated portion of the membrane.   
     
     
         3 . A device for detecting an analyte in a diluted liquid sample, comprising:
 (a) a compressible porous membrane for receiving a liquid, wherein the membrane allows for migration of the liquid from the point of application at a position other than a portion of the membrane to be isolated and allows sufficient migration to saturate the portion of the membrane to be isolated;   (b) first and second members adjacent opposing major surfaces of the membrane, wherein the first and second members are engageable to apply compressive force on top and bottom surfaces of the membrane along the perimeter of the area to be isolated, thereby defining a non-compressed area of saturated membrane centripetal to the compressed perimeter;   (c) a port adapted to receive delivery of a diluent, wherein the port is further adapted to deliver the diluent under pressure to the isolated portion of the membrane saturated with the liquid sample and to force the removal of the liquid sample from the isolated portion of the membrane;   (d) a receptacle in fluid communication with the isolated membrane for receiving the diluted liquid sample from the isolated portion of the membrane; and   (e) or more one test strips that are distinct from the sample receiving membrane, and in fluid communication with the receptacle, wherein the test strip(s) detect(s) the presence of analyte in the diluted liquid sample.   
     
     
         4 . The device of  claim 1 , wherein the migration of the first fluid along the membrane separates components in the first fluid. 
     
     
         5 . The device of  claim 1 , wherein the first fluid comprises whole blood and the isolated portion of the membrane contains its serum or plasma components. 
     
     
         6 . The device of  claims 2  and  3 , wherein the liquid comprises a biological fluid. 
     
     
         7 . The device of  claims 2  and  3 , wherein the migration of the liquid along the membrane separates components in the liquid. 
     
     
         8 . The device of  claims 2  and  3 , wherein the liquid comprises whole blood and the isolated portion of the membrane contains its serum or plasma components. 
     
     
         9 . The device of  claims 2  and  3 , wherein the isolated portion of the membrane defines a predetermined volume of the liquid sample. 
     
     
         10 . The device of  claims 2  and  3 , wherein the diluent is applied in a specified quantity. 
     
     
         11 . The device of  claims 2  and  3  that promotes mixing of isolated sample and diluent to produce a more uniformly diluted sample that collects in the receptacle by forcing the diluent and isolated liquid sample under pressure through a narrow channel located below the bottom of the isolated membrane and above the receptacle. 
     
     
         12 . The device of  claim 3  further comprising a control strip in fluid communication with the receptacle. 
     
     
         13 . The device of  claim 3 , wherein one or more test strips detect(s) the presence of an HIV antibody in the diluted liquid sample. 
     
     
         14 . The device of  claim 3 , wherein one or more test strips detect(s) the presence of an antibody to  H. pylori  antigen in the diluted liquid sample. 
     
     
         15 . The device of  claim 3 , wherein the test strip detects the presence of an HCG antigen in the diluted liquid sample. 
     
     
         16 . The device of  claim 3 , wherein the test strip detects the presence of any analyte that is a member of a specific binding pair, providing that a) one or both members of the binding pair retain(s) reactivity when bound to a visual marker and the complex of one pair member-visual marker is capable of migrating through the test strip and b) the other pair member retains reactivity when immobilized and dried on nitrocellulose or other test strip membranes and is capable of binding and retaining its specific binding pair member to its immobilized position where it can be visualized and interpreted in the test. 
     
     
         17 . A kit for detecting an HIV antibody comprising:
 (a) the device of  claim 3  with HIV antigen immobilized on the test membrane or membranes;   (b) a lancet or other device to collect whole blood by fingerstick;   (c) a transfer micropipet or other means of applying whole blood to the device; and   (d) a container containing a fixed quantity of suitable diluent, that mates with the port in the device and allows delivery of the diluent under pressure to the isolated portion of the compressible porous membrane.   
     
     
         18 . The kit for detecting an antibody to  H. pylori  comprising:
 (a) the device of  claim 3  with  H. pylori  antigen immobilized on the test membrane or membranes;   (b) a lancet or other device to collect whole blood by fingerstick;   (c) a transfer micropipet or other means of applying whole blood to the device; and   (d) a container containing a fixed quantity of suitable diluent, that mates with the port in the device and allows delivery of the diluent under pressure to the isolated portion of the compressible porous membrane.