Heating and cooling of sample materials is often required in some biological and other chemical reactions. For example, polymerase chain reaction (PCR) is a commonly used method in molecular biology to amplify DNA. The PCR takes advantage of multiple heating and cooling cycles to denature, anneal, and elongate the DNA. These changes in temperatures are typically accomplished by a thermocycler, which is expensive and constrain the user to relatively large reaction volumes. Therefore, a simple and inexpensive method for changing the reaction temperature that is amenable to a variety of reaction types and reaction volumes is desired.
Researchers at the University of Michigan have developed methods and microfabricated systems for running reactions, including PCR, in a Rayleigh-Benard convection cell. The system utilizes a novel application of Rayleigh-Benard convection principles for conducting biological or biochemical reactions, and contains a reaction chamber, solutions, starting molecules and a heat source (at or near the bottom of the reaction chamber). A cooling source is also provided at or near the top of the reaction chamber. The total reaction time can be limited by any applicable means including depletion of starting molecules, accumulation of reaction end-products or by-products, change in temperature, addition of a termination substance(s) or change in pH.
Applications and Advantages
- biological/ biochemical reactions and assays-nl-with temperature differential in reactant solutions
- microfabricated system
- removable, replaceable reaction chamber for-nl-the isolation of reaction products