Science Buddies: "Ask an Expert"

I would like to test the effects of different sound frequencies on DNA in saliva samples. I will measure absorbance and transmittance at different UV wavelengths using a spectrophotometer to see the effect on DNA. I need more information on using saliva samples and how to purify/preserve them...

- does the saliva have to be combined with anything?

- does saliva sample need to be purified and if so, is there a simplified method of purification that can be done at home?

- can the same saliva sample be used for multiple trials over several days and if so, does anything need to be done to preserve the sample?

Thank you for your help!

Hello gporter,

Sounds like an interesting project. This topic is well outside my experience and you may get a better response from posting your question on the Life, Earth and Social Sciences forum.

Saliva is a mixture of many substances so you'll need to extract and purify the DNA. One procedure for sampling oral cells and extracting the DNA is described here:

https://www.sciencebuddies.org/science- ... #procedure

A short online search on “DNA from saliva” turned up numerous references to procedures for handling saliva samples for DNA analysis. You may be able to use or modify one of those for your project work. And you might try searching with Google Scholar to get a greater number of technical references for your review.

DNA samples tend to decompose if heated or agitated. You may be able to keep refrigerated saliva extracts for several days.

I hope this helps. Please ask again if you have more questions.

A. Norman

Thank you so much for your reply and suggestions. I found a procedure for extracting the dna. I am still looking for the best way to purify the dna before testing it in the spectrophotometer.

I really appreciate your help!

Thanks