Solutions with agar should be autoclaved for 15 min at 121°C. The machine will heat the chamber to 121°C and keep it there for 15 min. When many large bottles are used, this might take a long time, but small volumes will reach this temp much faster, thus it is best not to mix very large (liter bottles) and small volumes in the same run.
For liquids that cannot be heated, use filter sterilization.
The autoclaves used are in the scullery ("Spülküche"). When making media mix the ingredients in the bottle:
- without water and indicate the amount of water that should be added. Leave the bottles in the scullery in the designated container. The liquid will be autoclaved in the morning and should be ready around 10am.
- add the water (from the filter in the scullery) and ask Bernadette or one of the other TAs to run the autoclave. This takes about 4 hours, so keep that into account when planning your day.
When autoclaving ‘dry’ consumables (toothpicks, pipette tips, empty bottles etc.) add a few droplets of water to improve autoclave efficiency. Dry them afterwards in the drying incubator (same room as autoclaves).
Material that can stand high temperatures can be sterilized in the 200°C oven.
Especially when boiling agar, be careful! Also when boiling in the microwave! Due to the heterogenic composition of components that are dissolved in the liquid temperatures differ which results in spontaneous boiling when bottles are moved. This can result in high pressures in bottles with a lid, which might break in such circumstances. Liquid agar is very hot and viscous, a great recipe for nasty burns! Wear lab coats when working with hot agar.
Open lids slightly before placing them in the autoclave by unscrewing caps by ½ turn to avoid pressure building up.