Science Buddies: "Ask an Expert"

My son and I are doing strawberry DNA extraction. How can the mixture be stored if it can be stored. what I'm asking is basically can the smash strawberries in the salt, soap and water mixture after it has been strained be stored in the refrigerator and if so for how long?. Or is it best to just simply make it upon presentation?. Help!

I would recommend leaving it no longer than a day in the fridge because it can grow bacteria and impact the results. Also the more fresh and alive the cells are the better your project will turn out.

Hello and welcome!

It would be best to make the strawberry mixture upon presentation as there will be no microbial DNA from storage/bacterial growth, or any contamination that may occur during the store process, especially due to potential mold or other growth.

However, adding ice-cold ethanol to the strawberry mixture can increase the amount of DNA that you are able to extract upon presentation from the strawberry mixture because the ethanol forms hydrogen bonds with the water in the mixture, which prevents the water from creating a protective case (formed by hydrogen bonds) around the DNA, which would minimize the amount of DNA you are able to extract from the mixture. The procedure for the version of the experiment that includes ethanol can be found here:

https://pbiol.rsb.org.uk/bio-molecules/ ... ing-things

Keep in mind that the ethanol portion of the experiment is optional, as you will still be able to extract a good amount of DNA from the strawberry mixture without the ethanol. Also, remember that ethanol is a potentially toxic chemical, so be extremely careful should you choose to use it in your experiment, and please be aware of all safety precautions that need to be made!

If you have any more questions, feel free to ask!
-cnoonan180