Immunological test element with improved control zone

Abstract

The invention concerns a test element for carrying out an immunological sandwich test for determining an analyte from a liquid sample containing a reagent zone or conjugate zone which contains a conjugate of an analyte binding partner and a label which can be detected directly or indirectly by visual, optical or electrochemical means (e.g., an enzyme, fluorescent or direct label, etc.) wherein the conjugate can be dissolved by the liquid sample, a detection zone which contains a permanently immobilized (i.e., which cannot be detached by the liquid sample) binding partner for the analyte or for complexes containing the analyte; and a control zone which contains a permanently immobilized binding partner for the conjugate of analyte binding partner and label characterized in that the control zone additionally contains one or more permanently immobilized binding partner(s) for the analyte or for complexes containing the analyte.

1 . A test element for carrying out an immunological sandwich test for determining an analyte from a liquid sample comprising: 
 a reagent zone which contains a conjugate of an analyte binding partner and a label which can be detected directly or indirectly by visual, optical or electrochemical means, wherein said conjugate can be dissolved by the liquid sample;    a detection zone which contains a permanently immobilized binding partner for the analyte or for complexes containing the analyte; and    a control zone which contains a permanently immobilized binding partner for the conjugate of analyte binding partner and label, wherein the control zone additionally contains one or more permanently immobilized binding partner(s) for the analyte or for complexes containing the analyte.    
   
   
       2 . The test element according to  claim 1 , wherein the permanently immobilized binding partners for the analyte or for complexes containing the analyte are the same in the detection zone and in the control zone.  
   
   
       3 . The test element according to  claim 1 , wherein the permanently immobilized binding partners for the analyte or for complexes containing the analyte are not the same in the detection zone and in the control zone.  
   
   
       4 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for the conjugate of analyte binding partner and label in the control zone is a polyhapten.  
   
   
       5 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for the analyte or for complexes containing the analyte in the detection zone is selected from the group consisting of antibody or immunologically active fragment of an antibody to the analyte; antigens, haptens or polyhaptens; and streptavidin or polystreptavidin.  
   
   
       6 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for the analyte or for complexes containing the analyte in the control zone is selected from the group consisting of antibody or immunologically active fragment of an antibody to the analyte; antigens, haptens or polyhaptens; and streptavidin or polystreptavidin.  
   
   
       7 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for the analyte in the detection zone is an antibody or an immunologically active fragment of an antibody to the analyte and the permanently immobilized binding partner for the analyte in the control zone is an antibody or immunologically active fragment of an antibody to the analyte.  
   
   
       8 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for complexes containing the analyte in the detection zone is streptavidin or polystreptavidin and the permanently immobilized binding partner for complexes containing the analyte in the control zone is streptavidin or polystreptavidin.  
   
   
       9 . The test element according to  claim 1 , wherein the permanently immobilized binding partner for complexes containing the analyte in the detection zone is streptavidin or polystreptavidin and the permanently immobilized binding partner for the analyte and/or for complexes containing the analyte in the control zone is an antibody or immunologically active fragment of an antibody to the analyte, and/or streptavidin or polystreptavidin.  
   
   
       10 . A method for detecting an analyte from a liquid sample comprising: 
 applying a sample to a test element according to one of the  claims 1  to  9 ;    reacting an analyte present in the sample with a labelled conjugate to form an analyte-conjugate complex;    binding the analyte-conjugate complex in the detection zone to the permanently immobilized binding partner for the analyte or for complexes containing the analyte;    binding the labelled conjugate that has not reacted with the analyte in the control zone to the permanently immobilized binding partner for the conjugate, and binding the analyte-conjugate complex in the control zone to the permanently immobilized binding partner for the analyte or for complexes containing the analyte.