Compositions for use as a signal generation component and methods of using same

Abstract

Compositions suitable for use as signal generation components of an immunoassay, and methods for their use. According to one aspect of the invention, the composition includes a carrier having a coating of an aminodextran and a metal chelate incorporated therein. The metal chelate is present in the amount of at least 0.065 μM per milligram of carrier, and the aminodextran coating density averaging at least about 45 μg per milligram of carrier. In another aspect of the invention, carrier is dyed with a complex having the formula: M (L1) x (L2) y , wherein M is a metal selected from the group consisting of europium, terbium, dysprosium, samarium, osmium and ruthenium; L1 is a ligand selected from the group consisting of DPP, TOPO, TPPO; L2 comprises a ligand having the formula wherein R is one or more substituents, each substituent comprising an electron donating group; n=2−10; x=1−2; and y=2−4.

1 . A composition suitable for use as a signal generation component in an immunoassay, comprising: 
 a carrier having a metal chelate incorporated therein, the carrier having a coating of an aminodextran, the metal chelate being present in the amount of at least 0.065 μM per milligram of carrier, the aminodextran coating density averaging at least about 45 μg per milligram of carrier.    
     
     
         2 . The composition of  claim 1 , wherein the metal chelate is present in the amount of about 0.065 μM to about 0.150 μM per milligram of carrier.  
     
     
         3 . The composition of  claim 1 , wherein the metal chelate comprises an europium complex.  
     
     
         4 . The composition of  claim 3 , wherein the carrier comprises a latex particle.  
     
     
         5 - 18 . (canceled)  
     
     
         19 . A method of detecting the presence or amount of an analyte in a test sample suspected of containing the analyte, the method comprising: 
 combining (i) the test sample (ii) a first specific binding partner, the first specific binding partner associated with a sensitizer, the sensitizer capable in its excited state of generating singlet oxygen, and (iii) a second specific binding partner, the second specific binding partner associated with a signal generation component comprising the composition of  claim 1;     allowing the formation of complexes comprising the first and the second specific binding partner, the complex formation brings the sensitizer into close proximity to the signal generation component;    activating the sensitizer to generate singlet oxygen;    measuring the amount of light emitted by the signal generation component as a measure of the analyte.    
     
     
         20 . (canceled)  
     
     
         21 . A composition of  claim 1 , wherein the metal chelate has the formula:  
         M (L1) x (L2) y , wherein M is a metal selected from the group consisting of europium, terbium, dysprosium, samarium, osmium and ruthenium;    L1 is a ligand selected from the group consisting of DPP, TOPO, TPPO;    L2 comprises a ligand having the formula                          wherein R is one or more substituents, each substituent comprising an electron donating group;    n=2−10;    x=1−2; and    y=2−4.    
     
     
         22 . The composition of  claim 21 , wherein each R is independently selected from the group consisting of C 1  to C 6  alkyls, dialkylamines, ethers, thioethers, and aryls.  
     
     
         23 . The composition of  claim 21 , wherein M comprises europium.  
     
     
         24 . The composition of  claim 21 , wherein n=3.  
     
     
         25 . The composition of  claim 21 , wherein x=1 and y=3.  
     
     
         26 . The composition of  claim 21 , wherein n=7.  
     
     
         27 . The composition of  claim 21 , wherein L2 comprises  
       
         
           
           
               
               
           
         
       
     
     
         28 . The composition of  claim 21 , wherein L2 comprises  
       
         
           
           
               
               
           
         
       
     
     
         29 . The composition of  claim 21 , wherein L2 comprises  
       
         
           
           
               
               
           
         
       
     
     
         30 . The composition of  claim 21 , wherein L2 comprises  
       
         
           
           
               
               
           
         
       
     
     
         31 . The composition of  claim 21 , wherein L2 comprises  
       
         
           
           
               
               
           
         
       
     
     
         32 . The composition of  claim 21 , wherein coating further comprises a second layer comprising a dextran aldehyde.  
     
     
         33 . The composition of  claim 21 , wherein the carrier further comprises an oxygen acceptor.