Real-time PCR in micro-channels
The present invention relates to methods for amplifying nucleic acids in micro-channels. More specifically, the present invention relates to methods for performing a real-time polymerase chain reaction (PCR) in a continuous-flow microfluidic system and to methods for monitoring real-time PCR in such systems.
1. A system for performing real-time PCR in a microfluidic device, said system comprising:
a microfluidic device comprising at least one channel configured to contain at least one test solution containing real-time PCR reagents and at least one carrier fluid;
a thermal transfer element integral with or proximal to the microfluidic device, said thermal transfer element configured to thermocycle the test solution along the length of a defined section of the at least one channel, wherein the defined section of the channel has a uniform temperature at any one time during temperature cycles for performing real-time PCR in the test solution within said defined section;
a source of illumination integral with or proximal to the microfluidic device and configured to illuminate the at least one channel; and
a detector integral with or proximal to the microfluidic device, said detector configured to detect a fluorescent signal at a plurality of locations along said defined section of said at least one channel.
2. The system of claim 1 , further comprising a software system that measures an average flow speed of the test solution in the channel.
3. The system of claim 2 , wherein said software system measures the average flow speed of the test solution by comparing sequential images of the fluorescent signal in the channel.
4. The system of claim 2 , wherein said software system measures the average flow speed of the test solution by comparing sequential images of a marker in the channel.
5. The system of claim 4 , wherein the marker is in the test solution.
6. The system of claim 4 , wherein the marker is in the carrier fluid.
7. The system of claim 2 , further comprising an element for controlling the flow speed of the at least one test solution continuously flowing in the at least one channel in response to the average flow speed measured by said computer system.
8. The system of claim 1 , wherein the fluorescent signal is measured at least once during each PCR cycle.
9. The system of claim 1 , wherein the detector is configured to detect a signal from amplification products and a signal from a marker at a plurality of locations along said defined section of said at least one channel.
10. The system of claim 9 , wherein the detector is configured to independently detect signals from the amplified product and the marker.
11. The system of claim 1 , wherein the at least one channel comprises a plurality of channels.
12. The system of claim 1 , wherein the at least one test solution comprises a plurality of test solutions.
13. The system of claim 1 , wherein the at least one carrier fluid comprises a plurality of carrier fluids.
14. The system of claim 1 , further comprising a sensor to detect the temperature of the thermal transfer element and to provide feedback information for controlling the temperature cycles.
15. The system of claim 9 , further comprising means for analyzing the amplified product.