The Agar Test and Bacteria Culture

The Agar Test

I completely forgot about this exciting experiment. I did this experiment 2 years ago, but I don’t know what to call it. I will call it… The bacteria experiment. This experiment is to let you culture (grow) bacteria. But I’m not going to do that experiment today. I wanted to check my agar.

Agar is a jelly-like substance, obtained from algae. Agar is derived from the polysaccharide agarose, which forms the supporting structure in the cell walls of certain species of algae, and which is released on boiling.

Simply, agar is the bacterias’ food. Let’s look at it.

I used half of it. I store it in my refrigerator and hid it deep in there so nobody can see it. If my mom sees that, it will be in the garbage bin because she doesn’t like chemicals to be with food. Anyway, I’m going to check it to make sure that it works properly. Wait, what’s this?

Expires on September 10th 2015?

…

This would not work. But I hid it so well though 😂.

And store it at 2-8°C (36-46°F)? My ‘fridge is only 10°C.

This can’t work. But you know, it may work.

It’s still frozen, so I’m going to boil the whole bottle if I remember 2 years ago. I need to clean everything, even the container that it’s going to be boiled in. I don’t want it to be contaminated.

To do the test you’ll need:

Things you’ll need: 2 petri dishes, beaker, alcohol lamp, agar, gloves, towels, and Q-tips.

Warning: Make sure everything is clean.

1. Boil the whole bottle of agar in the beaker. The agar will turn into liquid.
2. Pour the agar into the petri dishes; half way.
3. Use a Q-tip to collect bacteria. Rub it on dirty things (I used a shoe).
4. Rub the Q-tip that is dirty on to one petri dish. Leave the other one alone.
5. Place it in a dark place, cover it with half way a petri dish lid, and wait for 2-3 days.

If the dirty petri dish has dots on it and the other one doesn’t, your agar is fine.

If the dirty petri dish has nothing on it, the agar is bad.

But it looks like that it’s fine.

The clean one is one the left and the dirty is on the right.

The result is: my agar is fine.