Method for detecting the presence of a target nucleic acid sequence in a sample

Abstract

A method comprises loading a sample portion into a sample chamber which comprises means for minimizing diffusion of the sample portion, subjecting the sample portion to an amplification step, and determining whether the sample portion contains at least one molecule of a target nucleic acid. If the sample portion contains a single molecule of the target nucleic acid, the sample portion would attain a detectable concentration of the target nucleic acid after a single round of amplification. Also, a microfluidic device comprising a sample portion and a sample chamber comprising means for minimizing diffusion of the sample portion. Also, a microfluidic device comprising a sample chamber and an amplification targeting reagent positioned in the first sample chamber.

1 .- 9 . (canceled) 
     
     
         10 . A microfluidic device comprising:
 a first sample chamber; and   a first sample portion, said first sample portion being positioned in said first sample chamber, said first sample chamber comprising means for minimizing diffusion of said first sample portion, whereby if said first sample portion contains at least a single molecule of a target nucleic acid, said first sample portion would attain a detectable concentration of said target nucleic acid within a portion of said first sample chamber after a single round of amplification.   
     
     
         11 . A microfluidic device as recited in  claim 10 , wherein said means for minimizing diffusion of said first sample portion comprises at least one physical restraint on diffusion. 
     
     
         12 . A microfluidic device as recited in  claim 10 , wherein said means for minimizing diffusion of said first sample portion comprises at least one chemical restraint on diffusion. 
     
     
         13 . A microfluidic device as recited in  claim 10 , wherein said means for minimizing diffusion of said first sample portion comprises at least one feature selected from among flow restriction means, glass beads, gels, absorbent particles and electrophoretic means. 
     
     
         14 . A microfluidic device as recited in  claim 10 , wherein said first sample chamber further comprises constituents for enabling amplification of said target nucleic acid. 
     
     
         15 . A microfluidic device as recited in  claim 10 , wherein if said first sample portion contains at least a single molecule of said target nucleic acid, said first sample portion would attain a detectable concentration of said target nucleic acid within a portion of said first sample chamber after a single amplification step. 
     
     
         16 . A microfluidic device comprising:
 a first sample chamber, said first sample chamber comprising means for minimizing diffusion of said first sample portion; and   at least one amplification targeting reagent positioned in said first sample chamber,   whereby if a sample portion which comprises at least a single molecule of a target nucleic acid is positioned in said first sample chamber, said first sample portion would attain a detectable concentration of said target nucleic acid within a portion of said first sample chamber after a single round of amplification.   
     
     
         17 . A microfluidic device as recited in  claim 16 , wherein said means for minimizing diffusion of said first sample portion comprises at least one physical restraint on diffusion. 
     
     
         18 . A microfluidic device as recited in  claim 16 , wherein said means for minimizing diffusion of said first sample portion comprises at least one chemical restraint on diffusion. 
     
     
         19 . A microfluidic device as recited in  claim 16 , wherein said means for minimizing diffusion of said first sample portion comprises at least one feature selected from among flow restriction means, glass beads, gels, absorbent particles and electrophoretic means.