Science Buddies: "Ask an Expert"

Hi, I'm working on a project; Spectral Sensitivity of Binary Fission of Euglena, and I have trouble designing an experiment.

So my initial goal was to observe what color of light does Euglena reproduce well. I saw a paper about chloroplast development of Euglena in different intensity of light and thought it wasn't directly related to my topic, I read that Euglena's development can be affected by different light quality (spectrum), so I thought maybe their reproduction ability can be affected by light quality, too, like animal's reproduction or flower's blooming can be affected by light's period or intensity.

Anyway, I planned to design 4 black acrylic boxes with red, green, blue, and white LED lights on it. And I planned to grow Euglena in the those boxes respectively.

The point is, there are only few information about binary fission of Euglena or its life cycle and living conditions. I researched on the Internet about 2 months and I couldn't find a thing except Euglena reproduce by longitudinal binary fission and they grow in fresh inland water.

I wonder

1. What temperatures do they usually live
2. What factors affect their reproduction ability
3. What is their life cycle like
4. What kind of microscope do I have to use to observe Euglena

I know that it may seem a bit rude to question simple information on this forum, but since I am a bit exhausted with no result after two months, I hope someone who knows much better than be about Euglena would answer my question...

Thanks!

Hi,

I really like your project and i think it's an interesting question. I have never tried to grow Euglena but I know that food is usually the limiting factor for reproduction of single-celled organisms. Euglena is interesting because it can make its own food by photosynthesis or use the nutrients in pond water.

I would recommend that you buy the Euglena from Carolina Biologicals:

http://www.carolina.com/catalog/search- ... SearchForm

The Euglena culture comes with a manual on how to grow them and if you have questions you can call Carolina Bio's tech service and ask them how you can set up the growth chambers for illuminating them with different color LEDs. They are very happy to help young scientists!

As to the equipment you will need and the microscope, it would be really helpful if you could work in a school lab that already has a microscope, counting chamber, pipetters, etc for doing this kind of study. The microscope doesn't have to be that powerful since Euglena are relatively large and easy to see because of their color. The tricky part will be counting them because that is what you will have to do to measure their reproduction under the various conditions. There are special thick microscope slides called hemocytometers that have a ruled grating on them in the shape of a square with smaller squares within it that you can see through the eyepiece:

http://en.wikipedia.org/wiki/Hemocytometer

You count the number of Euglena within the square and use a formula for calculating the number of cells per milliliter. This gives you an accurate number that you can use to compare reproduction.

I hope this information helps get you going. You can always call people who work with Euglena and ask them questions. We have high school students doing projects in our lab every summer and we always tell them to ask all the questions they want. Don't be embarrassed to ask anything. Scientists were not born knowing all this stuff. We had to ask questions too. And we're still asking questions!

Good luck!

Sybee