Ultrafiltration & Diafiltration (UF/DF)

Purify & concentrate biomolecules, exchange buffers, and more

Get everything ready for the next step

Ultrafiltration (UF) and diafiltration (DF) are critical for the development and manufacturing of biological therapeutics, such as proteins, antibodies, and nucleic acids as well as therapies that rely on viral or lipid nanoparticle (LNP) delivery. They can be used separately or in combination to get the target molecule ready for the next processing step by enabling sample cleanup, purification, concentration, buffer exchange, and desalting. While both involve the use of membrane filters, they operate in slightly different ways.

What’s the difference between ultrafiltration and diafiltration?

UF uses a semipermeable membrane to separate molecules based on size and is typically used for purification and concentration. DF is the process of adding back a different buffer or solvent after UF.

Here’s how they work:

Use the force

UF uses a semi-permeable membrane with active force applied to drive filtration. Typically, force is applied by centrifugation or pressure.

Apply Force_R2_smaller
Size matters

The semi-permeable membrane retains larger target molecules while allowing smaller molecules to filter out. Regenerated cellulose (RC) is popular for gene therapy and biologics applications given its hydrophilic properties, low protein binding, and compatibility across a wide pH range.

Filtration diagram
Exchange that buffer

DF enables buffer exchange by adding new buffer to the retentate. The buffer is replaced, and the sample is returned to the original volume. At this point the UF/DF cycle can be repeated until the sample reaches a targeted level of replacement with the new buffer.

Exchange that buffer
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Big Tuna

Buffer exchange and sample concentration are the time consuming, hands-on chores you must deal with before all the things you really want to do. Big Tuna is a fully automated buffer exchange platform that uses a modified UF/DF method and gentle mixing to buffer exchange, concentrate, and clean up proteins, nucleic acids, or gene therapy vectors like AAVs and LNPs — with just 30 mins of setup time. Skip the slow and manual ways of prepping samples to free yourself up for other critical work.

More info

Gene therapy and biologics scientists can now use the right tool for buffer exchange and sample concentration with an automated platform that frees you up and delivers superior results. Have a question or ready to find out more?