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5 Nov 2013

Exactly a week ago, I started cultivating some bacteria using agar-agar in a petri dishes. Originally, I had wanted to take time-lapse photographs of the bacteria growth over time but gave up after 3-days when I did not see any progress. I had then chuck the petri dishes into the corner of my drawer.

So today I actually wanted to throw away the petri dishes and try cultivating the bacteria again for my time-lapse photographs, but noticed that are small colonies of bacteria growing in the petri dishes - I was thrilled. Having tried out extreme macro photography yesterday, I thought this might also be a good subject for it.

So here are the beautiful (or disgusting to some) extreme close-up photographs growing on the agar-agar in the petri dishes which you typically will not see with naked eyes. Pictures is at 25% magnification only. Please visit for the higher resolution and magnification of the photos …

The bacterias were cultivated based on sampling from 3 areas: (1) Car Steering Wheel, (2) Keyboard and (3) Rubbish Chute.

How I Cultivated the Bacteria ...

I must state clearly that cultivating bacteria is very dangerous as we definitely do not want to be infected by unknown bacterias. I'm not a scientist and whatever I'm experimenting with is based on what I'd had research and read from Internet. So if you are interested to also experiment with it, please make sure that you do sufficient research on the steps and risk involved, as well as all safety measures to protect yourself!

Items You Need

1. Petri dishes - you can get a dozen from ArtFriend at somewhere around $10.

2. Nutrient Agar - According to what I researched, all agars are actually gelatinous substance obtained from algae found in seaweeds. The difference of a "nutrient" agar is that it contains some percentage of beef/yeast extracts. As I could not find "Nutrient" Agar in supermarket or anywhere, I had used the normal agar-agar which we used to make desserts. 

3. Cotten Bud - For swabbing on areas where you want to sample the bacteria growth.

4. Sealing Tape or Masking Tape - this is to seal off the petri dishes.

The Steps to Cultivate

1. Mix the agar powder with water and cook to boil. Once boil, fill the petri dish to the mid-point with the liquid-form agar. Leave to cool down and solidify. They should be solidify within half an hour.

2. Take a cotton bud and swab around a target area which you would like to sample the bacteria (e.g. keyboard).

3. Once the agar is cooled down and solidify, take the cotton bud that has been swabbed and swab it across the surface of the agar. (Note: You may want to label your petri dish if sampling on various areas.)

4. Close the petri dish and seal it off with the sealing tape. Never to be opened again.

5. Bacteria grows in warm, moist and dark areas. So, store the petri dish in places such as the top of the refrigerator. Places the petri dish in turn-over position will help to keep the moist within. 

6. According to what I know, the bacteria should start growing in 2-3 days. In my case, nothing was found growing on the surface of the agar after 3 days which I'm suspecting could be due to the use of normal agar versus nutrient agar.

7. Dispose the entire petri dish after you have done your experimentation.


  1. Cool pictures, but most if not all of those are actually fungi, not bacteria! The second picture, for example, is certainly some Aspergillus species. That stringy, chained growth is hyphae, which are typical of fungi. Bacteria grow in shiny, gooey colonies!

  2. Hi, I wanted to provide some extra information too, since I work in a laboratory that often cultivates bacteria and fungi in petri dishes of agar media. You absolutely will need to add some nutrients to the media to get bacteria to grow; the only thing agar does is solidify the liquid into the jello-like substance they grow on. Fungi can deal with little to no nutrients...bacteria won't. Try adding something as simple as table sugar to the mixture next time and see if any bacterial colonies grow. If you add regular beef stock from the grocery store it will work even better. Good luck!