Science Buddies: "Ask an Expert"

Hi!

I'm going to culture Euglena and I want to see them forming colony, so...

1. Do I need to culture them in solid plate in petri dish to see colonies?

2. Then what kind of culture do I have to use?

3. Is there any way to hold the euglena in a certain phase of growth stage?
(I want to see them through microscope but then I have to take Euglena to school and I think they will grow on the way going to school...)

Hi,

If you want to see colonies of Euglena you will have to prepare sterile agar (usually 15 g per liter) in a liquid medium. Carolina Bio sells Euglena culture medium (http://www.carolina.com/biological-medi ... ure+medium). Is that what you were planning to use? You can also buy agar and Petri dishes from them.

Each 100 mm Petri dish holds about 25 mL of agar so figure out how many plates you want to make and multiply by 25 to get the number of mL you need. Add 1.5% agar and sterilize the medium by boiling it in the microwave. Do this on a low to medium power setting and watch it so that the liquid doesn’t boil over. Use a glass container that is about 4 times larger than the volume of liquid you are sterilizing. Five minutes of boiling is usually long enough. If you’ve never made agar and poured plates, check out this tutorial: https://www.sciencebuddies.org/science- ... Agar.shtml

Here’s a youtube tutorial on making and pouring agar plates: http://www.youtube.com/watch?v=OljTdYH_Wtg
Note that this video is specifically for making LB agar using ingredients added to distilled water. In your case, your Euglena growth medium is already prepared so all you have to weigh out is the agar. The video shows all the steps that you would follow if you were preparing plates in a lab rather than at home, but it is good to see the professional way to do this so you if you are making the plates at home you can try to duplicate it.

Euglena grow and divide only about once per 24 hours so they really do not grow very fast. If you want to transport the Euglena to school without having them divide you could chill the culture briefly in the refrigerator and carry it wrapped in aluminum foil so that no light gets to it.

I hope this answers all your questions. Let us know if you need more help.

Good luck!

Sybee