Hey Nigel,

Are you looking for a quick and dirty protocol for DNA extraction which will work in PCR and does not contain harmful substances? Or are you asking how to grind plant material without liquid nitrogen?

My two cents:

You can grind greater amounts of plant tissue using mortar and pestle and a small amount of sand (see sand e.g.) - in the following centrifugation steps you will get rid of the sand. I think this one will be suitable for your stiff and hard Cyperaceae.

Or you can use tube pestles for smaller amounts and then directly pipette your reagents in the tube containing the tissue.

There are several quick and dirty protocols available that allow you to get DNA quickly that will work in PCR but might not be of the best quality (hence "quick and dirty"). One protocol that is highly cited is by Wang et al (1993): A simple method of preparing plant samples for PCR.

This one works with small amounts of tissue that are placed in a tube, grinded in NaOH and then TRIS is added and voilá - ready for PCR. I used this one successfully on Brassica and Arabidopsis leaves and it worked equally good in comparison to the one-day DNA extraction protocol I normally use.

Good luck.

There are also several kits for "Plant Direct PCR", I'm using that one from Fermentas and it works very well. It comes with a robust non proof-reading Taq, but I tried it with an high-fidelity polymerase and it worked as well (less product anyway).

Thanks Alessandro - I had been considering them but getting funding from the college could be a problem. I am hoping if I can get a system up and running then I'll be able demonstrate importance of the application to the A level (16 - 48) syllabus in the UK.

The Wang et al (1993) sounds interesting (Thank you Susann) and we should have the chemicals in stock but it does leave me wondering what the catch is. A potential problem is does my water need to be deionised?

A level (16 - 18 year old students -not 48 as above - oops) syllabus in the UK