Extracting Onion DNA - Plastic vs. Glass

[BinaryBud]

Can anyone tell me if it will make a difference if the test tubes and measuring cups used in the Extracting Onion DNA experiment (https://www.sciencebuddies.org/science- ... p001.shtml) are made of glass or plastic? I know that plastic can react to some chemicals. This experiment uses dishwashing detergent, salt, meat tenderizer, and grain alcohol. Unfortunately all of our chemistry sets contain plastics.

Any advice/opinion will be appreciated.

[barretttomlinson]

Hi,

My personal preference would be to use glass test tubes if they are available for the alcohol precipitation step. You should not have any problems with the alcohol attacking any of the containers. Really the only reason that glass is preferable in the precipitation step is that glass is clear, so the dna precipitate may be easier to see. I did a version of this experiment using a strawberry, which worked quite well except the DNA was almost invisible until we collected it on a glass stirring rod. Then it acted kind of like a thin clear syrup that kind of drooled off the end of the stirring rod when the rod was pulled from the solution.

Good luck and have fun with the experiment!

Barrett Tomlinson

[BinaryBud]

Thank you for the response and I'm glad I asked! We'll try to locate glass test tubes and use existing plastic beakers.