Isolation of DNA

[Aoife Dunne]

Hi,

I'm a third year student of Biopharmaceutical & Healthcare Science in Galway-Mayo Institute of Technology, Ireland.

As part of the course, I have been studying the topic of Biotechnology. One of the experiments I have completed is the 'Isolation of DNA from buccal cells'. The protocol stated to use 95% ethanol to precipitate the DNA from solution. However, other protocols I have read specify the use of ice cold ethanol for this particular step in DNA isolation. So, I was wondering could anyone tell me if the ethanol should be ice cold or not?

Also, I would like to know the mechanism by which ethanol precipitates DNA.

Once the DNA is precipitated, I was wondering how long should the extracted DNA take to dissolve in 1 x SSC (15mM sodium citrate, 150mM NaCl, pH 8.0) buffer?

Finally, would someone be able to recommend a source from which a large amount of DNA can be extracted?

Thanks for all the help.
Aoife