Polytetrafluoroethylene (PTFE)
Hydrophobic membrane. Resistant to organic solvents as well as strong acids and bases. Low protein binding. Low in extractables. Main applications are the filtration of non-aqueous samples. Prior to filtering of aqueous samples the membrane must be pre-wetted with a water-miscible organic solvent.
Polyvinylidene difluoride (PVDF)
Hydrophilic membrane. Resistant to a broad range of organic solvents. Low protein binding.
Polypropylene (PP)
Slightly hydrophobic membrane. Resistant to a wide range of organic solvents.
Polyethersulfone (PES)
Hydrophilic membrane. Broad solvent compatibility. Suitable for filtration of aqueous and compatible organic solvents. Higher liquid flow than either PTFE or PVDF. Low in extractables. Low protein binding.
Nylon/polyamide (NYL)
Hydrophilic membrane. Resistant to a range of organic solvents. Suitable for use with high pH samples. Binds proteins, which makes it unsuitable for protein recovery applications.
Cellulose acetate (CA)
Hydrophilic membrane. Limited solvent resistance. Very low protein binding capacity, which makes it an excellent choice for protein recovery applications.
Cellulose nitrate (CN)
Hydrophilic membrane. Limited resistance to organic solvents. High liquid flow rate. High protein binding capacity, which makes it unsuitable for protein recovery applications.
Regenerated cellulose (RC)
Hydrophilic membrane. Resistant to a very wide range of solvents. Suitable for use with either aqueous solutions or organic solvents. Compatible with HPLC solvents. Very low protein binding capacity, which makes it an excellent choice for protein recovery applications. Anopore (ANP) (membrane used in Anotop™ filters) Anopore™ is a hydrophilic membrane with excellent organic solvent compatibility. Suitable for use with both aqueous and organic samples. The membrane has very tight pore-size distribution. Not suitable for use with very acidic or very basic samples.
Glass microfiber/glass fiber (GMF/GF)
Hydrophilic material. Excellent compatibility with organic solvents and strong acids (apart from hydrofluoric acid) and bases. Either used as a prefilter or as a final filter.