A sterilization filter, also known as a bacterial filter, is a specialized filter designed to remove or reduce the number of microorganisms (such as bacteria, viruses, and fungi) from a fluid or gas stream. Sterilization filters are commonly used in medical and biopharmaceutical applications, such as the filtration of air, water, or pharmaceutical products.

The mechanism of action of a sterilization filter is based on the principle of size exclusion. The filter contains a pore structure that allows the fluid or gas to pass through while trapping microorganisms. The pore size of the filter is carefully selected to ensure that microorganisms are removed or reduced to an acceptable level. Typically, the pore size of a sterilization filter ranges from 0.2 to 0.45 microns.

In addition to size exclusion, sterilization filters can also use other mechanisms to remove microorganisms. For example, some filters are treated with a coating of antimicrobial agents, such as silver or copper, that can kill or inhibit the growth of microorganisms on the filter surface.

It's essential to note that while sterilization filters are highly effective in removing microorganisms, they are not 100% foolproof. Therefore, it's crucial to follow appropriate filtration procedures and use filters that are validated for the intended application to ensure effective removal of microorganisms.