I work as a senior lab assistant at a university and one of my longer term tasks is to develop a DNA extraction protocol for medical student molecular biology class that could be completed, for the most part, within a 1,5 hour-long lesson.
I know there are plenty of easy DNA extraction protocols out there for demonstration, but the professor in charge who doesn't do any practical work themselves expect me to develop a protocol that not only works as a demonstration of a puffy cloud of extracted DNA, but which also produces DNA of sufficient quality for PCR amplification, while not using any particularly dangerous materials NOR any expensive ready-to-use DNA extraction kits. Basically, the expectation is to develop a fast, safe, effective DNA extraction protocol with cheap over-the-counter materials used for extraction and purification. I understand the enthusiasm and the educational value of being able to extract and amplify your own DNA, but this doesn't sound very feasible.
So far, I've been trying to tinker with the protocol I've added in the attachment that uses detergent and alcohols, but with a mouth rinse method I've only obtained very small concentrations of badly purified DNA. Besides the detergent, I've experimented with adding proteinase K, but considering the short time limits for the overall process, the short incubation period didn't help much either.
Can anyone suggest alternative protocols that might work, or am I right in thinking that with the given circumstances the expectations for developing such a DNA extaction protocol are very unrealistic?