Hobbies And Interests
Growing Bacteria
Agar can serve as a nutrient for growing bacteria in a small petri dish. It̵7;s a good way to demonstrate how much bacteria can be found in a day to day environment such as the office or home. To grow the bacteria, the agar is heated in water till it̵7;s dissolved and then poured into a petri dish. Wipe a cotton swab on whatever it is you want to test, whether it̵7;s a kitchen worktop or the stapler on your desk. Draw a line in the agar with the cotton swab and then place the petri dish in a clear sealed bag and leave it in a warm place. Within a few days you will start to see mold, fungus or other bacteria growing in the agar.
Disinfectants
If you want to test the effectiveness of disinfectants such as hand gels or cleaning agents, you can first grow bacteria in a petri dish with agar in the manner described above. Before storing the dish in the clear bag, dip a cotton swab into the disinfecting agent and dab it in the dish as if you were drawing dots. When the bacteria starts to grow, the areas with the disinfectant should be clean. There might even be halos around the microbes where the disinfectant was dabbed.
Starch Content
By placing fruits in agar that has been dissolved in water, it is possible to view the starch content of the fruits. First place the agar in a petri dish and then add fruits to it. Pour iodine into the dish and then pour it off after a couple of minutes. The contents of the petri dish will change color. The blue areas are where starch is present.
Clarifying Juice
Bartenders use clarified lime juice to add to cocktails, as it looks more appealing than cloudy juice when mixing with other ingredients. This can be done with the aid of special equipment or by using agar. The agar must be boiled in water and then the lime juice can be added. The two liquids are whisked together and placed in a dish or bowl surrounded by ice so that it sets. You̵7;ll be left with lumps of ̶0;curd̶1; which you can strain with a cheesecloth, and the clear juice will be left.