Build your own PCR machine

This system does precise temperature control (heating and cooling) of the reaction vessel, which is filled with your sample DNA and the right enzymes.

There are other systems which benefit from precise temperature control: make chocolates (getting the right consistency depends on following the right temp curve), sous-vide cooking, SMD soldering ovens, there emerges a need for generalized PID (proportional-integral-derivative) temp controllers. But hey, one's just emerged! http://brettbeauregard.com/blog/2012/01/introducing-the-ospi...

I wasn't aware what a PCR machine does and the website assumes you already know! PCR is a technique that allows scientists to create a vast quantity of a specific sequence of DNA (via http://answers.yahoo.com/question/index?qid=20091226132510AA...).

Funny anecdote: the original PCR experiments were done with water baths at various temperatures. They manually moved the DNA samples from the boiling water (denaturation), to hot water (55-ish degrees, annealing) to hotter water (elongation, 70ish) and then back to the boiling water for another round of amplification.