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Investigate the effect of [[antiseptic]]s and [[antibiotic]]s on [[bacteria]]l colonies.
===Method===
*[[Dependent Variable]] - The antiseptic or antibiotic used.*[[Independent Variable]] - Observe the growth of colonies.*[[Control Variable]]s - The same quantity of antiseptic and antibiotic. The same spread of [[bacteria]] applied to the growth medium. Incubated for the same length of time. Incubated at the same temperature. Only one type of [[bacteria]] used. #Agar plates prepared with [[bacteria]] will be supplied.#Mark the underside of an agar plate into three sections making a dot in the centre of each, labeling them 1,2 and 3 and writing your initials and the date on the agar plate.#Spray the work space with disinfectant and wash your hands with antibacterial soap.#Take a small circle of filter paper and soak it into one of the three antiseptics/antibiotics.#Place the circle onto the dot marked at the centre of a section.#Repeat steps 4 and 5 ensuring the antiseptics are not mixed in any way.#Use two pieces of sellotape to attach the lid loosely to the top of the agar plate (to ensure oxygen get in).#Incubate at 25°C for 48 hours.#Measure the diameter of the area in which [[bacteria]] did not grow.