AAV concentration & reformulation

The problem

AAVs are often produced in dilute volumes that need to be cleaned up and concentrated. Tackling this process with centrifugal filtration devices or one at a time flow filtration instruments is labor intensive, especially at high sample numbers and volumes. Viral vectors like AAV need rapid clean up and buffer exchange workflows that don’t compromise the integrity of the sample and have high recovery.

The right tools for the job

Unagi is the first benchtop buffer exchange platform that brings together all the painful, hands-on steps it takes to clean up and concentrate AAV samples into a working range. Unagi uses ultrafiltration/diafiltration (UF/DF) to exchange 1 to 8 samples from a starting volume of 0.5 to 8 mL. Unagi keeps careful track of sample volumes during a run, filters samples down and knows what volumes to add back to each sample. It repeats this until each sample hits the target percent exchange or AAV concentration.

Take it down

Unagi uses a consumable called the Una. Each Una holds 0.5 to 8 mL of sample and Unagi handles 1-8 sample per run. They use regenerated cellulose membranes with 10, 30, and 100 kDa molecular weight cutoffs to make sure your samples stay put, don’t get absorbed, and the liquid passes right through — with ≥96% recovery.

Served up a'la carte

Big Tuna is a fully automated buffer exchange system that provides a more uniform sample handling approach and degrees of process control that you just can’t get with manual methods. Big Tuna uses a modified ultrafiltration/diafiltration (UF/DF) method to exchange and concentrate AAVs and other viral vectors. Big Tuna monitors the sample volumes during the run, adds back the filtered volume and gets your samples to the right percent exchange and AAV concentration every time.


Big Tuna uses a plate-based consumable called the Unfilter. All Unfilters use a regenerated cellulose membrane which is ideal for viral vectors because it minimizes non-specific binding. They come in 2 formats, 24-well (0.45 – 8 mL) or 96-well (100 – 450 µL). The Unfilter 96 is available with molecular weight cutoffs of 3, 10, 30, and 100 kDa. The Unfilter 24 has 10, 30, and 100 kDa MWCOs. The higher molecular weight cutoffs are perfect for large viral vectors and Unfilter 24 can concentrate up to 48 mL down to 8 mL.


The proof

Get your AAV to its happy place

AAV stability can be impacted by changes to buffer pH, salts, and ionic strength. When Unagi or Big Tuna partners up with Uncle, a wide range of these conditions can be studied without using tons of sample. Both buffer exchange solutions can gently exchange your AAVs into various conditions without disrupting the capsids. Then Uncle can come in and assess the AAV capsid stability in those conditions based on the temperature that the genome begins to eject.

Get your AAV to its happy place_R2


Buffer exchange and concentration are two of the most annoying things you have to do before you can work with your sample. It takes forever, you physically have to be there and just when you think it’s done, you’re tweaking it again. Unagi is the first completely hands-free benchtop buffer exchange solution that’s made to take this not-so-fun task off your plate — so you can be anywhere else instead of tied to your bench.

Big Tuna front_crop

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, plate-based 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. Skip the slow and manual ways of prepping samples to free yourself up for other critical work.

Want more info?

Want to learn more about how Unagi and Big Tuna can handle your AAV concentration and reformulation with ease?