Centrifuge filters are useful for performing several filtrations/concentration at the same time
Consist of receiver tube and filter insert. Three types available:
Micro-Spin: 900 µl filter insert for 2 ml micro tube with hinged cap
Midi-Spin: 5 ml filter insert for 7 ml tube with hinged cap
Maxi-Spin: 25 ml filter insert for 50 ml with screw cap
Made of polypropylene. Maxi-Spin with high density polyethylene screw cap
All stated volumes are max. volumes. Working volumes should be lower
Available with eight different types of microfiltration membranes in two pore sizes.
In general, centrifuges with a fixed angle rotor head are recommended.
Remark: Avoid touching the membrane when filling and decanting the insert
All types are available with 0.2 µm and 0.45 µm membranes.
Nylon: Naturally hydrophilic with wide solvent resistance. Also suitable for aqueous samples with pH range 3-10. Binds proteins.
Polyethersulphone: Hydrophilic and low binding of proteins. Resists pH 1-4.
PVDF: Hydrophilic membrane type. For solvent filtration as well as aqueous filtrations. Low protein binding.
Regenerated Cellulose: Hydrophilic and low protein binding. Solvent resistant.
PTFE: Hydrophobic membrane. Resistant against solvents, acids and bases. Not recommended for aqueous samples.
Polypropylene: Hydrophobic but can also be used for filtration of water based samples. Solvent resistant. Well suited for filtration of samples prior to ion chromatography.
Cellulose Acetate: Hydrophilic and low protein binding membrane. Also resistant against some alcohols.
Nitro Cellulose: Hydrophilic (wetting agent added) membrane type. For aqueous samples. Will bind proteins