Investigate the effect of different antibiotics on bacteria

Heat forceps over a Bunsen burner until they burn bright orange label the petri dishes one for the mast rings and the other for water as the control use the sterile forceps to place a mast ring in one of the petri dishes under the Bunsen burner use the sterile forceps to dip a disk of paper into some ethanol then let it dry over the Bunsen dip the disk in water then place the disk in the other petri dish tape the petri disk lightly then incubate at 30°C for 24 hours measure the zone of inhibition carry out repeats to find the mean