A membrane-type filtration, often executed as crossflow filtration for separating submicron-sized particles or dissolved macromolecules. The cut point of ultrafiltration membranes is often characterized by the so-called MWCO (Molecular Weight Cut Off).

Lowered absolute pressure acting against a surrounding atmospheric pressure. This underpressure, also known as vacuum, can be decreased in low vacuum filtrations only down to the vapor pressure of the liquid, i.e. the underpressure for water at room temperature and sea level can be decreased down to 0.2 bar a.

If the term suspension does not make sense anymore for a liquid to be separated such as in a sterile filtration, it may be called an unfiltrate.

Thickening of suspensions, meaning an increase of the solids concentration.