System and method for confining reagents within a fluidic device

Abstract

A method for inserting and retaining a reagent within a disposable cartridge of a diagnostic assay system. The method includes the steps of: (i) drying a reagent in combination with a carrier, and (ii) inserting the carrier, with the dried reagent, into an open end of one of the assay chambers, wherein the carrier facilitates insertion of the pellet into a chamber without contact by an operator.

What is claimed is: 
     
         1 . A method for retaining a reagent within a disposable cartridge of a diagnostic assay system, the disposable cartridge having at least one assay chamber for holding and mixing assay fluids, comprising the steps of:
 drying a reagent in combination with a carrier; and   inserting the carrier, with the dried reagent, into an open end of one of the assay chambers, wherein the carrier comprises a pod enclosing the dried reagent and having a by-pass filter at one end to facilitate rehydration of the dried reagent upon injection of an assay fluid into the assay chamber.   
     
     
         2 . The method of  claim 1 , wherein the carrier comprises a cap having an open end for receiving the dried reagent and a closed end for enclosing the open end of the assay chamber. 
     
     
         3 . The method of  claim 2 , wherein the diagnostic assay system comprises a cartridge rotor that contains the at least one assay chamber, the method further comprising:
 overturning the cartridge rotor to facilitate insertion of the cap upwardly into the open end of the assay chamber.   
     
     
         4 . The method of  claim 1 , wherein the carrier comprises a plug-spring having a spring element with the dried reagent attached to one end of the spring element and configured to: (i) plug the open end of the assay chamber and (ii) bias the dried reagent downwardly into the assay chamber. 
     
     
         5 . The method of  claim 4 , wherein the spring element is a coil spring extending along an elongate axis of the chamber. 
     
     
         6 . A method for retaining a reagent within a disposable cartridge of a diagnostic assay system, the disposable cartridge having at least one assay chamber for holding and mixing assay fluids, comprising the steps of:
 forming a pellet of dried reagent;   combining the dried pellet with a carrier configured to be received within one of the assay chambers of the disposable cartridge; and   inserting the carrier, with the dried pellet, into an open end of one of the assay chambers,   wherein the carrier comprises a pod enclosing the dried pellet and having a by-pass filter at one end to facilitate rehydration of the dried pellet upon injection of an assay fluid into the assay chamber.   
     
     
         7 . The method of  claim 6 , wherein the carrier comprises a cap having an open end for receiving the dried pellet and a closed end for enclosing the open end of the assay chamber. 
     
     
         8 . The method of  claim 7 , wherein the diagnostic assay system comprises a cartridge rotor that contains the at least one assay chamber, the method further comprising:
 overturning the cartridge rotor to facilitate insertion of the cap upwardly into the open end of the assay chamber.   
     
     
         9 . The method of  claim 6 , wherein the carrier comprises a plug-spring having a spring element with the dried pellet attached to one end of the spring element and configured to: (i) plug the open end of the assay chamber and (ii) bias the dried pellet downwardly into the assay chamber. 
     
     
         10 . The method of  claim 9 , wherein the spring element is a coil spring extending along an elongate axis of the chamber. 
     
     
         11 . A disposable cartridge comprising:
 a carrier disposed in at least one assay chamber of the disposable cartridge and configured to secure a dehydrated reagent, the carrier being configured to facilitate rehydration of the dehydrated reagent upon the introduction of an assay fluid into the assay chamber,   wherein the carrier comprises a pod enclosing the dehydrated reagent and having a by-pass filter at one end to facilitate rehydration of the dehydrated reagent upon injection of the assay fluid into the assay chamber.   
     
     
         12 . The disposable cartridge of  claim 11 , wherein the carrier comprises a cap having an open end for receiving the dehydrated reagent and a closed end for enclosing the open end of the assay chamber immediately prior to use. 
     
     
         13 . The disposable cartridge of  claim 11 , wherein the carrier comprises a spring element projecting from a plug configured to be retained within a rim of an open-ended assay chamber, the spring element being configured to bias the dehydrated reagent downwardly into the assay chamber. 
     
     
         14 . The disposable cartridge of  claim 12 , wherein, after loading the cap with the dehydrated reagent, the cap is filled with an inert gas and includes a detachable cover to contain the inert gas within the cap to reduce oxidation of the dehydrated reagent.