Prepare the UV lamp with dish exposure setup. Turn it on in order to heat up and to start emitting full spectral range.
Work in pairs. Carefully open the dish lid, and put the bottom part under the UV lamp. Prepare the stopwatch and start it when the UV cover is removed. After the exposition time is over,close the UV cover.
Procedure 5
Spread the bacteria lightly and equally over the nutrient surface whilst rotating the dish from left to right using the hockey stick.
Repeat the procedure for all of the different type of bacteria in the group (0s,30s,60s,90s)
Procedure 4
Procedure 6
Remove the dish, cover it with lid and put it aside.
Repeat the procedure for all exposition times.
Incubate the dishes over night.
Pipet 0.06 mL of the bacteria onto the surface of the Petri dish. Dispose used tips in a biohazard bag. This is to reduce the spread of bacteria.
Take the hockey stick out of the ethanol then light briefly on the burner. Hold it under the burner to let it burn and cool down.
Procedure 3