Method for determining an analyte in a fluid

Abstract

A reagent strip for measuring the concentration of glucose in whole blood has a polymer on at least one side thereof to increase the opacity thereof, thereby reducing the effect of hematocrit on the glucose determination.

1 . A method for determining analyte concentration in a fluid sample, the method comprising the acts of:
 (a) providing a test strip having a sample side and a reaction side, the test strip including a porous membrane, the test strip being adapted to accept a sample on the sample side and pass it towards the reaction side, said test strip including a testing reagent, said testing reagent comprising a color-indicator system that changes color to indicate the presence of the analyte in the sample, said test strip further having a polymer on at least the reaction side, said polymer increasing the opacity of at least a portion of the test strip after contact with a sample, said polymer being selected from the group consisting of acrylic latex polymers, polystyrene sodium sulfate polymers, and combinations thereof;   (b) applying the sample to the sample side of the test strip; and   (c) determining the analyte concentration of the sample using information from the color indicator system.   
   
   
       2 . The method of  claim 1  wherein the test strip includes a handle, the handle being attached to the porous membrane, the handle forming an aperture to receive the sample. 
   
   
       3 . The method of  claim 1  wherein the test strip includes a handle, a disc and an optically clear window, the handle forming an aperture, the disc being fitted within the aperture and including the porous membrane, the optically clear window being applied over the disc and a portion of the handle. 
   
   
       4 . The method of  claim 1  includes a handle, a ribbon and a spacer, the ribbon including the porous membrane, the spacer forming a capillary inlet and being applied over a portion of the strip and ribbon. 
   
   
       5 . The method of  claim 1  wherein the analyte is glucose. 
   
   
       6 . The method of  claim 1  wherein said porous membrane includes polyethersulfones, modified polyethersulfones, or combinations thereof. 
   
   
       7 . The method of  claim 1  wherein the testing reagent includes a glucose oxidase oxidative system. 
   
   
       8 . The method of  claim 1  wherein said testing reagent includes a glucose dehydrogenase (GDH) system. 
   
   
       9 . The method of  claim 1  wherein the color-indicator system includes tetrazolium compounds. 
   
   
       10 . The method of  claim 1  wherein the color-indicator system includes tetrazolium salt compounds. 
   
   
       11 . The method of  claim 1  wherein the reagent comprises a mediator including a substituted or unsubstituted 3-phenylimino-3H-phenothiazine. 
   
   
       12 . The method of  claim 1  wherein the reagent comprises a mediator including a substituted or unsubstituted 3-phenylimino-3H-phenoxazine.