Prefilter in glass microfiber (GF/GMF): Hydrophilic glass microfiber membrane, which can be used for solutions with high particle load or high viscosity, e.g. soil samples and fermentation media. The high chemical resistance of GF glass microfiber allows the filtration of aggresive solutions and solvents.

Surfactant-Free Cellulose Acetate (SFCA): Hydrophilic membrane with even lower protein binding than normal CA filters.
SFCA differs by not containing the surfactants normally present in CA filters. These surfactants help loweing the surface tension af water through the filters, and because SFCA lack them, we reach even lower adsorption of water, proteins, sera, and culture media.