Expert: Dana Krempels, Ph.D. - 12/10/2008

Question
How is it possible to measure oxygen consumption in geminating Seeds? is there a specific piece of apparatus needed?

Answer
Dear Lorna,

There are many different ways to measure this, but the simplest is with a respirometer.  Unfortunatey, even this very simple device requires something that will absorb the carbon dioxide produced by respiration (so you don't confuse it with oxygen, since the respirometer measures only the change in volume of the gas in the chamber, and doesn't identify the gas), and the respirometer chamber must be air-tight so the germinating seeds don't photosynthesize, producing oxygen.  (Yes, even germinating seeds begin to produce chlorophyll very soon after germination begins!).

You can read my lab manual chapter on measuring respiration here:

http://www.bio.miami.edu/dana/151/gofigure/

Click on Lab #6 (Respiration).

There are also very expensive devices that can measure the gases present in a closed sample, but these are probably far beyond what you would be able to acquire for a high school or university project.

Hope this helps.

Dana