See full answer to your question here. Similarly one may ask, why is Gatorade used to collect cheek cells?
The sports drink contains salt at a concentration compatible with the osmotic in the environmentof the cells. The sports drink prevent the cells from breaking open and releasing there DNA before they are collected.
Beside above, what experiments can you do with your DNA? Strawberry DNA extraction
Besides, why does the alcohol have to be cold in DNA extraction?
Alcohol, being a charged molecule itself, serves to pull DNA, also charged, out of the water. Salt from earlier in the process helps the DNA stick together and “clump”. The ethanol needs to be ice-cold for two reasons: Colder temperatures lower the energy of the molecule better.
Why would it be better to use an isotonic sports drink than plain water?
The chemical properties of the sports drink helps to restore chemicals that the body has previously used and therefore the sports drink is more isotonic (definition: equal osmotic pressure) for the cells as opposed to using plain water.