Biological contamination
Biological contamination is caused by the growing of biological material (originating from samples or otherwise). It should not be confused with other kinds of chamber contamination mentioned in Cleaning the glass chamber. Biological contamination of the chamber is typically detected by a high O2 flux at closed chamber near air saturation. It is detected by a sensor test, an instrumental background test or by observing the flux at closed chamber for a short time routinely before any experiment. In the later two cases the high flux contamination may be caused by biological contamination of the chamber itself or by a contaminated medium. This can be tested by observing the flux in pure water. The ideal counter agent is 70% Ethanol with 30% water (NOT 100% Ethanol). Prevention of biological contamination of the chamber is primarily by storage under 70% ethanol. If repeated washing with 70% Ethanol does nor remove an already present biological contamination, the glass chamber has to be cleaned as described for Protein contamination under Cleaning the glass chamber by removing the glass chamber form the instrument and using a strong acid.
