Science Buddies: "Ask an Expert"

Hi I am trying to figure out how to measure dna. In our project we are exposing DNA with radiation. I have experience in gel electrophoreis and agar plates. I would like to know if there is a machine that can measure DNA precisely.

Hi Roy,

This is a great subject for a science project! There are a number of methods for measure DNA:

DNA adsorbs UV light at 260 nm, so if you have a spectrophotometer that measures absorbance at this wavelength and if you DNA is in solution, this would be a good method. Here is a typical protocol with details included:

http://www.mc.vanderbilt.edu/root/pdfs/ ... ometer.pdf

Here is a site that includes a method for measuring DNA using ethidium bromide, which is a fluorescent molecule, This would be suitable for samples that are in agarose gels. This dye is carcinogenic, so you need to be careful when working with it.

http://www.protocol-online.org/prot/Gen ... on/index.h
ml

Do you have access to a lab with a densitometer? Please let me know more details about your experiment and what resources you have available. This will help identify the optimum method for you to use.

Donna Hardy