When impurity removal needs to be efficient and economical and also involves a large volume of sample, Tangential Flow Filtration (TFF) may be the best option. TFF uses a filter to separate or isolate certain-sized particles. Unlike traditional (or dead end) filtration, the fluid is circulated across rather than forced through the filter, establishing a pressure differential.
This “tangential” filtration means the sample flows parallel to the filter and is recycled numerous times through a reservoir. Particles that are smaller than the pore size are pushed through as filtrate. TFF, also referred to as cross-flow filtration, includes microfiltration, nanofiltration, and ultrafiltration.
With TFF, thicker particles do not build up or cake the filter, which increases the filter usability. Other benefits include:
A researcher wanted to study the viruses that inhabit the intestines of a cow. To conduct his research, he set up a system using a ?Masterflex® L/S® Peristaltic Pump and pump head with silicone tubing, pressure gauges, and fittings to mount gauges inline and to connect to the filter. He ran samples from a reservoir through the peristaltic pump and the pressure gauge into the tangential flow filter. He used two filters in separate processes: a 0.2 µm filter to remove bacteria and a
<100 kD filter to concentrate the viruses.
This system produced results with a higher concentration of viruses captured by the tangential flow filter than that from a system with less filtration control.
Tangential flow filtration has been used in the wine industry for some time to remove cellular debris, produce cleaner wine, and save costs on bottling final filters. The quality of the wine itself also improved. TFF has been used in food processing for decades and when used in pharmaceutical processing and manufacturing, allows continuous protein purification.
TFF can handle a large surface area and filter larger volumes without clogging. It is ideal for larger-scale lab separations such as cell harvesting or protein isolation from culture supernatants (the clear fluid above a sediment or precipitate). Specific applications include: