Polymerase chain reaction (PCR) remains the major method for amplifying nucleic acids like DNA and RNA. Although most well-equipped high school science labs have a thermal cycler (the instrument used to cycle between the temperatures needed to conduct the reaction), these instruments are expensive and inaccessible to many schools. If only there were a way to amplify nucleic acids that would be less expensive, and that the students could build themselves. Well, there is!
Catherine Klapperich and colleagues at Boston University described such a method last year in a poster and accompanying paper at uTAS, the international conference on miniaturized chemical analysis systems. The temperature control system they describe could not be simpler. It is two sytrofoam cups and two chemical toe warmer packets. That’s it. They use this combination to do a reaction related to PCR, but instead of requiring two or three different temperatures, this reaction requires only one (an isothermal amplification).
The paper shows fantastic temperature stability over 30 minutes, more than enough time to amplify scant amounts of starting DNA into quantities sufficient for analysis using gel electrophoresis. The one downside to this technique is that it requires a microfluidic chip, which students would likely not be able to produce on their own (at least using the method presented in the paper). So, if a small-volume container with good thermal conductivity and low evaporation could be easily made, this method would be easily amenable to in-class amplification of nucleic acids at a fraction of the cost of purchasing a thermal cycler.
Any students out there looking for an awesome research project?