Microfluidic Analysis System

Abstract

A thermal cycling device ( 3 ) device a number of fixed thermal zones ( 11, 12, 13 ) and a fixed conduit ( 10 ) passing through the thermal zones. A controller maintains each thermal zone including its section of conduit ( 10 ) at a constant temperature. A series of droplets flows through the conduit ( 10 ) so that each droplet is thermally cycled, and a detection system detects fluorescence from droplets at all of the thermal cycles. The conduit is in a single plane, and so a number of thermal cycling devices may be arranged together to achieve parallelism. The flow conduit comprises a channel ( 17 ) and a capillary tube ( 10 ) inserted into the channel. The detection system may perform scans along a direction to detect radiation from a plurality of cycles in a pass.

1 - 23 . (canceled) 
     
     
         24 . A microfluidic analysis system comprising a thermal cycling device, the device having a plurality of fixed thermal zones and a fixed conduit passing through the thermal zones, a controller for maintaining each thermal zone including its section of the conduit at a constant temperature, a pumping system for flowing a series of droplets through the conduit so that each droplet is thermally cycled, and a detection system for detecting electromagnetic radiation from droplets at a plurality of said thermal cycles. 
     
     
         25 . The microfluidic analysis system of  claim 24 , wherein the conduit comprises a channel with a circular cross-section. 
     
     
         26 . The microfluidic analysis system of  claim 25 , wherein the conduit comprises a channel and a capillary tube inserted into the channel. 
     
     
         27 . The microfluidic analysis system of  claim 26 , wherein the capillary has a circular cross-section. 
     
     
         28 . The microfluidic analysis system of  claim 26 , wherein the channel and capillary are configured to receive a refractive index-matching liquid in the channel and at least partly surrounding the capillary. 
     
     
         29 . The microfluidic analysis system as claimed in  claim 28 , wherein the channel has a depth greater than that of the capillary. 
     
     
         30 . The microfluidic analysis system of  claim 26 , wherein the conduit is in a single plane. 
     
     
         31 . The microfluidic analysis system of  claim 26 , wherein the thermal zones are mutually thermally insulated. 
     
     
         32 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises optics for focusing incident light radiation. 
     
     
         33 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises optics for filtering incident radiation. 
     
     
         34 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises optics for filtering emitted radiation. 
     
     
         35 . The microfluidic analysis system of  claim 26 , wherein the detection system performs scans along a direction to detect radiation from a plurality of cycles in a pass. 
     
     
         36 . The microfluidic analysis system of  claim 26 , wherein the detection system performs simultaneous detection of emitted light from a plurality of cycles. 
     
     
         37 . The microfluidic analysis system of  claim 26 , wherein there is an air gap between adjacent thermal zones. 
     
     
         38 . The microfluidic analysis system of  claim 26 , wherein said air gap is adjustable. 
     
     
         39 . The microfluidic analysis system of  claim 26 , wherein the conduit passes through a hot thermal zone for a length before a first cycle, providing a denaturation zone. 
     
     
         40 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises a plurality of optic fibers for point illumination of each of the plurality of cycles. 
     
     
         41 . The microfluidic analysis system of  claim 40 , wherein the optic fibers are placed at each loop of the capillary tube. 
     
     
         42 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises a plurality of optic fibers for point detection of each of the plurality of cycles. 
     
     
         43 . The microfluidic analysis system of  claim 42 , wherein the optic fibers are placed at each loop of the capillary tube. 
     
     
         44 . The microfluidic analysis system of  claim 26 , wherein the detection system comprises a rotating filter for cyclic filtering of incident or emitted light. 
     
     
         45 . The microfluidic analysis system of  claim 26 , wherein the conduit is in a serpentine pattern of multiple folds, each fold extending through a plurality of thermal zones. 
     
     
         46 . The microfluidic analysis system of  claim 26 , wherein the microfluidic analysis system comprises a plurality of thermal cycling devices arranged in parallel. 
     
     
         47 . The microfluidic analysis system of  claim 26 , wherein the detection system performs simultaneous detection of emitted light from a plurality of cycles from a plurality of thermal cycling devices. 
     
     
         48 . The microfluidic analysis system of  claim 26 , wherein the microfluidic analysis system comprises two or more of the thermal cyclic devices, allowing parallel processing of droplet trains. 
     
     
         49 . The microfluidic analysis system of  claim 26 , further comprising a pumping system maintaining the flow of droplets through the conduit. 
     
     
         50 . A method of performing a nucleic acid amplification reaction, the method comprising:
 a) providing a biological sample;   b) segmenting the sample into droplets which are wrapped in an immiscible oil;   c) directing the flow of the droplets in oil though a conduit passing through a plurality of thermal zones under conditions sufficient for the amplification reaction to occur; and   d) detecting an output of the amplification reaction in one or more droplets.   
     
     
         51 . The method of  claim 50 , wherein the conduit comprises a capillary tube inserted into the channel. 
     
     
         52 . The method of  claim 50 , wherein said detecting is performed throughout multiple cycles of the amplification reaction. 
     
     
         53 . The method of  claim 50 , wherein the plurality of zones comprises at least three different thermal zones. 
     
     
         54 . The method of  claim 50 , wherein the detecting is performed by detecting fluorescence signal emitted from the droplets. 
     
     
         55 . The method of  claim 50 , wherein the detecting is performed using a plurality of optic fibers for light transport. 
     
     
         56 . The method of  claim 50 , wherein the droplet length is about 0.5 mm. 
     
     
         57 . The method of  claim 50 , wherein the droplet diameter is about 400 μm. 
     
     
         58 . The method of  claim 49 , wherein the droplet spacing is about 1.5 mm. 
     
     
         59 . The method of  claim 49 , wherein the droplet velocity is about 1 mm/s. 
     
     
         60 . A device adapted to perform the method of  claim 46 . 
     
     
         61 . A method of performing a nucleic acid amplification reaction, the method comprising:
 a) creating a flow of spherical droplets of sample contained in an immiscible carrier fluid;   b) passing the flow through a circular tubing in a thermal cycler;   c) controlling three thermal zones in said thermal cycler;   d) controlling the carrier fluid velocity by an external pumping system;   e) passing the sample through the thermal zones allowing the nucleic acid amplification reaction to occur in the droplets;   f) optionally, repeating step e); and   g) detecting of the amplification reaction.   
     
     
         62 . The method of  claim 61 , wherein the carrier fluid is an oil. 
     
     
         63 . The method of  claim 61 , wherein the amplification reaction is a polymerase chain reaction.