Filtration is different from other sterilization filter methods. Wikipedia defines sterilization filter as a process that eliminates (removes) or kills (deactivates) all forms of life and other biological agents. Up until now all the sterilization filter methods we covered deactivate or kill bacteria and viruses. Filtration is the first and only sterilization filter method that eliminates bacteria by separating the microorganisms from the sterilized medium, but unlike other sterilization filter methods, it doesn’t kill or stop the bacteria's ability to reproduce. The way it works is actually very simple. You’re probably familiar with water filters found in an office or at home, or a coffee percolator, all of which use the same basic mechanism of filtration.

Sterilization filter uses membranous filters that have tiny pores that let the liquid pass through but prevent bigger particles such as bacteria to pass through the filter. Therefore, the smaller the pore, the more likely the sterilization filter is to stop more things from going through it. If the pores of a filter, which is designed to remove a microbe, which is a microscopic organism, are small enough, they should be able to stop all living things from passing through.