Hi Selene,

If you mean by "dry cycle autoclaving" the "dry sterilization" by oven at high temperatures, the presence of a little amount of water isn't a problem. However, if you mean by it the "wet cycle autoclaving" method, the presence of a little volume of water inside the glassware is necessary for efficiently destruction of microorganisms.

Selene Franziska Hess Shore

Place soiled glassware and lab ware in secondary containers and autoclave them in the solids cycle. Do not fill containers more than 2/3 full with liquids. Loosen caps or use vented closures. In case of clean glassware and wrapped instruments, lay them in a secondary container before autoclaving in wrapped goods cycle.

There are several options. It seems that if you autoclave on a dry cycle, those problems should be resolved unless you are in a high humidity environment. Autoclave in paper sterilizing bags, allow the normal cool down period and store in a cool dry environment. There should be no condensation using this method and if there is, have the autoclave checked.

Alternative is to heat sterilize glass ware. This can be cone by covering any opening with aluminum foil and placing it in an drying oven at 160° C for 2 - 2.5 hours. If you are sterilizing Pasteur pipettes with cotton plugs, careful not to keep at that temperature for longer than 2 hours as the cotton will burn if left too long. Dry heat indicators are useful to identify glassware that has been heat sterilized as their indicator strips change color once exposed to the sterilizing temps.

The leftover water on the glassware should not be a source of contamination from the thermophilic bacteria (B. stearothermophilus). This organism is used as an indicator organism for the sterilization process.