Do Sterlitech Track Etch filter membranes have any type of wetting agent on them?
A. Sterlitech Polycarbonate Track Etch filter membranes use a very mild wetting agent; PVP (Polyvinylpyrrolidone) to make them more hydrophilic and more easily wettable. PVP is a very useful and safe chemical, originally used as a blood plasma extender in surgeries. PVP does have some effects in chemotaxis where the cells seem to migrate faster with PVP on the membrane that, in certain chemotaxis experiments, is not desirable. However, in most cases, PVP is negligible and does not affect any analysis beign performed with the Sterlitech Track Etch membrane. Sterlitech Polycarbonate Track Etch filter membrane is available with or without PVP. Sterlitech Polyester Track Etch membrane is natrually hydrophilic, therefore, it is made without PVP. Click here for for a technique to remove the PVP wetting agent from polycarbonate membranes.