Systems and methods for the amplification of DNA

A system for amplifying DNA, comprising:

• a microfluidic chip comprising a sample channel and a heat exchange channel formed within the microfluidic chip sufficiently close to the sample channel such that a heat exchange fluid in the heat exchange channel can cause a sample in the sample channel to gain or lose heat at desired levels, wherein the heat exchange channel is configured to exchange heat with two sides of the sample channel;
• a first reservoir having an output port coupled to an input of the heat exchange channel through a first forward valve and having an input port coupled to an output of the heat exchange channel through a first return valve, said first reservoir storing a first heat exchange fluid;
• a second reservoir having an output port coupled to the input of the heat exchange channel through a second forward valve and having an input port coupled to the output of the heat exchange channel through a second return valve, said second reservoir storing a second heat exchange fluid;
• a third reservoir having an output port coupled to the input of the heat exchange channel through a third forward valve and having an input port coupled to the output of the heat exchange channel through a third return valve, said third reservoir storing a third heat exchange fluid, wherein each of the first, second, and third reservoirs is divided into two chambers fluidly connected with each other by a valve, the fluid being released into the heat exchange channel from a first chamber and returned back from the heat exchange channel into the second chamber;
• temperature control means for:
• (a) regulating the heat exchange fluid stored in the first reservoir at a first temperature, (b) regulating the heat exchange fluid stored in the second reservoir at a second temperature, and (c) regulating the heat exchange fluid stored in the third reservoir at a third temperature;
• an imaging system including an excitation source and an image capturing device for imaging a biological reaction within the sample channel;
• pump means for pumping said heating exchange fluids out of said reservoirs;
• and
• control means for operating said return valves and said pump means such that:
• (a) for a first period of time, the first heat exchange fluid stored in the first reservoir is able to enter the heat exchange channel, but the second and third heat exchange fluids stored in the second and third reservoirs, respectively, are not able to enter the heat exchange channel;
• (b) for a second period of time, the second heat exchange fluid stored in the second reservoir is able to enter the heat exchange channel, but the first and third heat exchange fluids stored in the first and third reservoirs, respectively, are not able to enter the heat exchange channel;
• and
• (c) for a third period of time, the third heat exchange fluid stored in the third reservoir is able to enter the heat exchange channel, but the first and second heat exchange fluids stored in the first and second reservoirs, respectively, are not able to enter the heat exchange channel, wherein
• the first period of time is different than the second period of time, which is different than the third period of time, and
• the first temperature is different than the second temperature, which is different than the third temperature, wherein the first heat exchange fluid is returned back to the first reservoir prior to directing the second heat exchange fluid to the heat exchange channel and the second heat exchange fluid is returned back to the second reservoir prior to directing the third heat exchange fluid to the heat exchange channel.

A thermal exchange system for microfluidic systems comprising:

• at least one heat exchange channel, wherein the at least one heat exchange channel is configured to carry a heat exchange fluid, wherein the heat exchange channel is configured to exchange heat with a portion of a sample channel, wherein the sample channel is configured to carry a genomic sample in a buffer, wherein the at least one heat exchange channel is configured to exchange heat with two sides of the sample channel;
• and
• at least two reservoir tanks, a first reservoir tank and a second reservoir tank, wherein the first reservoir tank is configured to include a first heat exchange fluid at a first temperature, and the second reservoir tank is configured to include a second heat exchange fluid at a second temperature, wherein alternatively either the first or the second heat exchange fluids can be directed into the at least one heat exchange channel, wherein a flow control system is configured to return the first heat exchange fluid back to the first reservoir tank prior to directing the second heat exchange fluid to the heat exchange channel, wherein each of the at least two reservoir tanks has an input and output port coupled to at least one heat exchange channel through two separate valves, wherein each of the first and second reservoir tanks is divided into two chambers fluidly connected with each other by a valve, the fluid being released into the heat exchange channel from a first chamber and returned back from the heat exchange channel into the second chamber;
• wherein the at least one heat exchange channel and the sample channel are formed in a single microfluidic chip;
• and
• an imaging system including an excitation source and an image capturing device for imaging a biological reaction within the sample channel.