طريقة أخرى لتحديد حجم الميكرون للأعمدة ، 0.45 um لـ> 3 um ، و 0.22 um for<3um. 0.45 um membranes are typically used for general filtration and particle removal while 0.2/0.22um membranes, or sterilizing-grade membranes, are most commonly used for solution sterilization (bacteria removal).