Biotech Tangential Flow Filtration
Pall's line of biotech cross-flow filtration products (TFF) range from single-use modules to cleanable cassettes, and from standard lab and benchtop systems to fully customizable process systems. These products are also scalable and allow for optimal use of available space.
Develop biotech tangential flow filtration applications using only a few milliliters of sample and scale up using the same membranes to pilot and full scale processes in excess of 10,000 liters. Our supporting services ease the implementation of biotech TFF technologies into your processes through training, trials, validation, and technical support. Pall partners with our customers to design the best products to address each purification challenge.
Cross Flow Filtration In Biotech
Tangential Flow Filtration Introduction
Tangential Flow Filtration (TFF), also called Cross Flow Filtration (CFF), is a rapid and efficient method for filtration and separation of solutions containing biomolecules, or particles such as viruses, bacteria or cellular material. It is a process whereby product flow (feed) is directed tangentially along the surface of a membrane with most of the solution circulated back to the feed tank.
The rapid flow of feed solution across the membrane acts to 'sweep' the surface, reducing concentration polarization (product concentration at the membrane surface). It also prevents build-up of foulants that can plug the pores at the membrane surface. The rapid cross flow creates a pressure drop, which forces some of the feed solution and dissolved molecules that are smaller than the pores in the membrane, through the membrane filter. The solution that passes through the membrane is referred to as filtrate or permeate. Molecules or particles larger than the membrane pores are retained in the feed solution and effectively concentrated.
Membrane filtration can be classified as either a microfiltration (MF) or ultrafiltration (UF) process. Microfiltration membranes, with pore sizes typically between 0.1 micron and 1 micron, are generally used for clarification, sterilization and removal of micro-particulates or for cell harvesting. Ultrafiltration membranes, with much smaller pore sizes between 0.001 and 0.1 micron, are used for concentrating and desalting dissolved molecules (protein, peptides, nucleic acids, carbohydrates and other biomolecules), exchanging buffers, fractionation and water purification. Ultrafiltration membranes are typically classified by Molecular Weight Cut Off (MWCO), rather than pore size.
The fluid dynamics of cross flow filtration reduces membrane fouling and maintains filtration rates (flux) for a longer period of use, thus increasing membrane throughput (greater capacity) compared to traditional cartridge (direct flow) filtration. Additional advantages of TFF include the ability to reuse the filter modules and relatively low capital costs.
Tangential Flow Filtration can be applied to a wide range of fields within biotechnology. It is applicable to R&D discovery applications right through pilot and full-scale production. TFF can be used to concentrate and desalt sample solutions ranging in volume from a few milliliters to thousands of liters. It can be used to fractionate large from small biomolecules, harvest cell suspensions and clarify fermentation broths and cell lysate.
Tangential Flow Filtration Applications In Biotech
Microfiltration and ultrafiltration processes incorporating tangential flow or cross flow filtration is utilized in a wide range of biopharmaceutical applications. Examples of a few typical applications are listed below:
- Concentration and desalting of protein, peptide, and oligonucleotide solutions
- Purification and recovery of antibodies or recombinant proteins
- Vaccine and conjugate concentration and diafiltration.
- Fractionation of protein mixtures
- Blood plasma fractionation and purification
- Cell broth clarification, concentration
- Cell culture perfusion such as in monoclonal antibody (mAb) production
- Clarification of Fermentation broths
- Concentration and washing of bacterial cells
- Water and buffer purification (endotoxin removal)