Cell biology - aseptic techniques

Sterilise work area

With disinfectant to kill microorganisms that could cause contamination

Sterilise equipment and culture medium

By steaming at high pressure in autoclave or use UV light/gamma radiation to kill microorganisms that could cause contaminiation

Sterilise inoculating loop

By dipping in ethanol and heating in Bunsen burner flame until red hot (don't place down or blow on it)

Open lid of petri dish

near Bunsen burner to create convection currents and reduce chance of microorganisms entering

Lift lid of petri dish

at an angle and replace quickly to avoid air getting in

Fix lid

with adhesive tape to prevent air getting in or microorganisms escaping

Don't seal lid all the way around

to allow oxygen in to prevent growth of harmful anaerobic microorganisms and to allow respiration

Incubate

At maximum 25oC to reduce chance of growing pathogens

Store petri dishes

upside down so condensation doesn't fall and affect growth