In early origin of the study of bacteria, the used of autoclave and steam chamber design by Koch and Pasteur, they are used for sterilizing culture media. The media to be sterilized is allowed to stand in the incubator for several days before the day to be used. On the technique the contaminated flask where discarded, while the sterile one are used for the sterilization. There is biological indicator where the organism is naturally present in the environment; the only flask discarded was the one that has been extremely contaminated with the growth of bacteria. In this technique of testing sterility self indicator enhances the simplest way of achieving the result, but without the self indicator, sterility monitoring becomes extremely difficult. The self indicator is determined with the material in question, it only difficult when using material that is not self indicated. The use of statistical plan is very important in this technique because it help to achieve a standard confidence of the result.
Process Control: many electrical autoclave are build with thermocouple inside in which the load is been placed during sterilization. For perfect actualization of sterility, media bottle is placed into an identical bottle containing the some volume of water with that of the load to be sterilized so that the status of sterilization temperature are confirm with the load. Load setting are validated by putting thermocouple in different position within the chamber and the representative sample. The setting is to examine either there is any hot or cold spot leave, these chart are used to design cycle autoclave needed to obtain a desired sterilization of that load configuration. Remember that thermocouple are made up of multiple point in case of placing the load, they are place on the multiple point of thermocouple. The test is not compulsory carried out in a regular other, but are carried out whenever a change occur in the pack, size, and shape of the material which are to be sterilized with the autoclave.