Tangential Flow Filtration Product Selection Guide
|Tangential Flow Filtration (TFF) is a rapid and efficient method for separation and purification of biomolecules. It can be applied to a wide range of biological fields such as immunology, protein chemistry, molecular biology, biochemistry, and microbiology. TFF can be used to concentrate and desalt sample solutions ranging in volume from 10 milliliters to thousands of liters. It can be used to fractionate large from small biomolecules, harvest cell suspensions, and clarify fermentation broths and cell lysates.
Easy Product Selection
Consider the Biomolecule of Interest
Your biomolecule of interest, or product, can be retained and separated from the low molecular weight contaminants, or it can be passed and purified from higher molecular weight contaminants and particles.
In general, a membrane with a molecular weight cut off (MWCO) should be selected that is three to six times smaller than the molecular weight of the protein to be retained. Other factors can also impact the selection of the appropriate MWCO. For example, if flow rate (or processing time) is a major consideration, selection of a membrane with a MWCO toward the lower end of this range (3x) will yield higher flow rates. If recovery is the primary concern, selection of a tighter membrane (6x) will yield maximum recovery (with a slower flow rate). These values should be used as a general guide, as solute retention and selectivity can vary depending on many factors, such as transmembrane pressure, molecular shape or structure, solute concentration, presence of other solutes, and ionic conditions.
Our membranes are highly selective and typically achieve recoveries in the range of 95 – 99%. The narrow pore size distribution of these membranes results in minimal molecule retention of molecular weights below the MWCO of the membrane.
Consider Fluid Characteristics
Sample concentration and viscosity determine the type of channel that is required for the process run. Most TFF cassettes are available in screen or suspended screen configurations.
Tangential Flow Channel Configurations
In the screen channel configuration, a woven separator creates gentle turbulence in the retentate flow, minimizing membrane fouling. Screen channel configuration is used with a clean filtered 0.2 μm solution (free of particles or aggregates that can get trapped in the screen).
Screen channel available in:
- Minimate™ devices
- Ultrasette™ devices
- LV Centramate™ cassettes
- Centramate cassettes
The suspended screen channel configuration has a more open structure in the retentate channel that provides better performance when highly viscous or particle-laden solutions are being processed.
Suspended screen available in:
- Ultrasette devices
- LV Centramate cassettes
- Centramate cassettes
Consider the Sample Volume and Processing Time
Choosing the appropriate cassette or device size depends on the total sample volume, the required process time, and the desired final sample volume. Performance parameters for Pall Life Sciences’ laboratory TFF devices are presented below.
General Product Selection Based on Starting Sample Volume
||50 cm2 (0.05 ft2)
||30 - 40 mL/min
||25 - 1000 mL
||< 10 mL
||0.01 m2 (0.1 ft2)
||60 - 80 mL/min
||40 - 2000 mL
||0.02 m2 (0.2 ft2)
||120 - 160 mL/min
||60 - 4000 mL
||0.084 m2 (0.9 ft2)
||1200 - 1500 mL/min
||0.2 - 5 L
||0.093 m2 (1.0 ft2)
||600 - 800 mL/min
||0.2 - 25 L
* Data is per unit or cassette. Centramate holder can hold five cassettes. Other column data can be calculated by multiplying table values by the number of cassettes installed in the holder.
** Typical filtrate flow rate is based on an average filtrate flow rate of 50 LMH and a process time of about four hours. Actual value may be higher or lower depending on the MWCO of membrane, sample composition and viscosity, operating conditions, i.e., transmembrane pressure, cross flow rate, temperature, etc.
*** Minimum concentrated volume depends on system hold-up volume, reservoir design and pump type and speed. Smaller volumes can be achieved by minimizing tubing lengths and use of properly sized components, tubing, fittings, etc.