Sample-acquiring microfluidic tester

Abstract

A microfluidic device and method of its use. A workable microfluidic device ( 100 ) includes a channel ( 116 ) extending between an entry aperture ( 230 ) and a vent ( 118 ). Part of the channel ( 116 ) is arranged to permit interrogation of particles carried by a fluid passing therethrough. Suction structure carried on the device ( 100 ) is disposed in fluid communication with the channel operably to apply a reduced pressure at the entry aperture ( 230 ) effective to infuse an amount of fluid through the entry aperture and into a receiving zone ( 122, 122′, 122″ ) of the channel. The entry aperture ( 230 ) is placed into a bulk fluid, and the suction structure is operated to load a sample into the microfluidic device ( 100 ).

What is claimed is: 
     
         1 . An apparatus, comprising:
 a channel configured and arranged to permit fluid flow through an interrogation device, a portion of said channel being arranged to permit interrogation of particles carried by a fluid passing therethrough;   an entry aperture communicating through said channel to a vent; and   suction structure of said interrogation device disposed in fluid communication with said channel and operable to apply a reduced pressure through a portion of said channel to said entry aperture effective to infuse an amount of fluid through said entry aperture and into a receiving zone of said channel.   
     
     
         2 . The apparatus according to  claim 1 , wherein:
 said interrogation device comprises electrode structure configured and arranged to permit particle interrogation according to the Colter effect.   
     
     
         3 . The apparatus according to  claim 1 , wherein:
 said interrogation device comprises radiation transmitting structure arranged to permit detection of fluorescence conventionally known as a Stokes' shift.   
     
     
         4 . The apparatus according to  claim 2 , wherein:
 said interrogation device further comprises structure arranged to permit detection of fluorescence conventionally known as a Stokes' shift.   
     
     
         5 . The apparatus according to  claim 1 , wherein:
 said interrogation device comprises a plurality of stacked thin film layers, a portion of said channel being formed as a void caused by at least one layer.   
     
     
         6 . The apparatus according to  claim 1 , wherein:
 said suction structure comprises a suction bulb.   
     
     
         7 . The apparatus according to  claim 5 , wherein:
 said suction structure comprises a void space disposed in at least one interior layer and covered by an exterior layer.   
     
     
         8 . The apparatus according to  claim 5 , wherein:
 said suction structure comprises a suction bulb.   
     
     
         9 . The apparatus according to  claim 5 , wherein:
 said suction bulb is formed in an exterior layer as a transversely off-set area.   
     
     
         10 . The apparatus according to  claim 1 , wherein:
 a portion of said channel is configured to urge particles toward substantially single-file travel there-through.   
     
     
         11 . A method for loading a fluid sample into a microfluidic interrogation cassette, comprising the steps of:
 a) providing a microfluidic interrogation cassette comprising:
 a channel configured and arranged to permit fluid flow in a direction from an entry aperture toward a vent, a portion of said channel being arranged to permit interrogation of particles carried by a fluid passing therethrough; and 
 suction structure carried by said interrogation cassette and disposed in fluid communication with said channel operably to apply a reduced pressure through a portion of said channel to said entry aperture effective to infuse an amount of fluid through said entry aperture and into a receiving zone of said channel; 
   b) applying a bias sufficient to displace said suction structure to a pre-suction configuration in preparation to apply said reduced pressure;   c) placing said entry aperture into bulk fluid; and   d) releasing said bias to load said sample.   
     
     
         12 . The method according to  claim 11 , wherein:
 step b) is performed before step c).   
     
     
         13 . The method according to  claim 11 , wherein:
 step b) is performed after step c).