Sterilization Procedure

We were going to use 10% bleach solution to sterilize the duckweed fronds before placing them to grow in the sterile media. However, the problem with this method is that if you bleach the fronds for too long, the plants will die - if you bleach them for too short of a time, not all the bacteria will be killed. In order to combat this issue, we bleached each sample for a different amount of time: 15 seconds, 30 seconds, 1 minute, and 1 minute 30 seconds.

So the methods:
A few duckweed samples were transferred into a petri dish filled with tap water using an inoculating loop. An inoculating loop was then used to pick one clone and transfer it to a small watchglass filled with about 10 mL of 10%bleach solution; as soon as the plant was immersed in bleach, the timer was started. After 15/30/60/90 seconds, the plant was immediately removed with a new inoculating loop and placed into a new petri dish with sterile water for rinsing and observation (I was looking for a small green bud zone which would indicate that the sample was still alive) Then using a new sterile inoculating loop, the samples were transferred into their appropriate sterile flasks with minimal exposure time to air. A new sterile rinsing petri dish was used for each clone.