Week 4-Assignment :Cultivating Microbes

Assignment：Cultivate Microbs and test the funtion of the DIY sterile hood.

1.Gather the materials and appliances.

2.Prepare the culture medium.2.Prepare the culture medium.2.Prepare the culture medium.

3.The Petri dishes and media are wrapped in a newspaper and sterilized in a high pressure steam sterilizer.

4.Open the petri dish as little as possbile and pour the cultivation medium inside.Shake gently to cover the petri dish surace and let it solidify.

5.Label the Petri dishes. Put two of them in the DIY sterile hood and expose to air. Expose the other two Petri dishes outside. Another one sealed as a blank control.

6.Two days later, observe the results. In the Petri dishes as blank control, there was no bacteria. In the Petri dishes inside the DIY sterile hood, there were only a small amount of bacteria. And More bacteria were in the Petri dishes outside the sterile hood. This shows that the sterile hood can have a certain degree of aseptic effect.