Apparatus and method for multiplex analysis
The present invention provides miniaturized instruments for conducting chemical reactions where control of the reaction temperature is desired or required. Specifically, this invention provides chips and optical systems for performing and monitoring temperature-dependent chemical reactions. The apparatus and methods embodied in the present invention are particularly useful for high-throughput and low-cost amplification of nucleic acids.
1. A system for varying the temperature of a reaction sample comprising:
(a) a chip comprising an array of at least 1000 fluidically-isolated micro wells for containing and confining a liquid reaction sample, wherein each individual micro well has: i) a volume of less than 1 μl, and ii) an upper surface and a closed bottom surface, wherein said chip is free of micro-capillaries or other channels;
(b) a bottom heating element in thermal communication with the closed bottom surface of the chip;
(c) a transparent cover encompassing at least peripheral dimensions defining the upper surface of said at least 1000 micro wells,
wherein the transparent cover comprises; i) a glass plate with a top surface and a bottom surface, wherein said bottom surface is closer to said chip than said top surface, and ii) an indium tin oxide heater on said bottom surface of said glass plate, and wherein said indium tin oxide heater is in thermal communication with the upper surface of at least one of said at least 1000 micro wells; and
(d) a computer readable medium operably linked to said bottom heating element and said indium tin oxide heater, wherein said computer readable medium has stored thereon an algorithm that controls the bottom heating element and said indium tin oxide heater to effect:
i) cycling of said bottom heating element between a primer annealing temperature, a primer-dependent extension temperature, and a denaturation temperature, and
ii) heating of the indium tin oxide heater to a temperature that prevents condensation of said liquid reaction sample during said cycling of said bottom heating element.
2. The system of claim 1 , wherein at least one micro well is sealed with an adhesive layer over an open surface of the micro well.
3. The system of claim 2 , wherein the adhesive layer is made of a polymer.
4. The system of claim 1 , wherein the transparent cover comprises a plurality of indium tin oxide heaters.
5. The system of claim 1 , wherein at least one micro well has a dimension of about 10 mm to about 100 μm in length, about 10 mm to about 100 μm in width, and about 10 mm to about 100 μm in depth.
6. The system of claim 1 , wherein at least one micro well has a volume of from about 100 μl to about 0.001 μl.
7. The system of claim 1 , wherein the transparent cover comprising the indium tin oxide heater seals the upper surface of said at least 1000 micro wells.
8. The system of claim 1 , further comprising a photon-sensing element.
9. The system of claim 1 , wherein the chip is operatively coupled to an optical system that detects optical signals emitted from the liquid reaction sample.
10. The system of claim 1 , wherein the chip has a ramp temperature time about 25° C. or higher per second.
11. The system of claim 1 , wherein each micro well further comprises a temperature sensor in thermal contact with the micro well.
12. The system of claim 1 , wherein the bottom heating element alone is used to vary the temperature without the aid of an external heat sink.
13. The system of claim 1 , wherein at least one micro well further comprises a plurality of grooves at the bottom surface.
14. The system of claim 1 , further comprising a light source configured to provide excitation wavelength to said at least 1000 micro wells through said transparent cover.
15. The system of claim 1 , wherein the surface of the micro wells are etched.
16. The system of claim 1 , wherein the surface of the micro wells are coated with materials to reduce the possibility that the liquid reaction sample will interact with the surface of the micro wells.
17. The system of claim 1 , wherein the micro wells are coated with a hydrophobic coating.