Home > Products >


Big Tuna

Unchained Labs

Buffer exchange is the time consuming, hands-on chore you have to deal with before all the things you really want to do. Big Tuna automates the entire tedious process and puts all the control at your fingertips. Exchange one protein, 96 or anything in between. It handles big and small volumes with high precision, so you’ll sail through exchanges without a hitch.

Go big or keep it small

Big Tuna serves up two consumables to tackle any volume requirement. Use Unfilter 96 to exchange as little as 100 µL on as many as 96 different samples at the same time. Unfilter 24 lets you go big and exchange as much as 8 mL on up to 24 samples. No matter how you roll, Big Tuna can handle it.

Always come out even

Big Tuna keeps buffer exchange even across the plate with its unique pressure-based UF/DF and gentle mixing. Its acoustic sensor measures the volume in every well before and after each cycle to track every sample’s exchange rate. Then Big Tuna figures out on the fly how much buffer to add to even things out.

Be a control freak

Buffer exchange doesn’t have to be a shot in the dark or keep you anchored to the bench. Big Tuna gives you full, hands-off control over how efficiently the process happens. Take it slow and easy with delicate proteins or fast-track the sturdy ones. Big Tuna nails the final protein concentration and gets you to next steps quicker.

Know it all

You’ll be a Big Tuna expert on the first try. Use the software wizard to drag and drop your proteins and buffers into place — Big Tuna handles the rest. It’ll tell you exactly where to put everything else and how much buffer you’ll need. After the run starts, check in on progress anytime and know exactly when your exchange is done.


Buffer exchange volume range
Unfilter 24: 0.45-8 mL
Unfilter 96: 100-450 μL

Unfilter 24: Up to 24 formulations in parallel
Unfilter 96: Up to 96 formulations in parallel

Exchange time at full volume (96%, at 10 mg/mL IgG)
Unfilter 24: 4.5 hours*
Unfilter 96: 3 hours*

Protein concentration (range): Up to 200 mg/mL*
Target concentration accuracy: ± 10%*
Protein recovery: >96%*


Volume measurement: Ultrasonic sensor
Exchange pressure: 60 psi
Operating temperature: Room temperature

Buffer exchange orbital mixing
Unfilter 24: Optimized at 700 rpm
Unfilter 96: Optimized at 875 rpm
Duty cycle programmable

96 cm L x 81.2 cm D x 130 cm H, 220 kg (instrument)
160 cm L x 100 cm D x 198 cm H, 270 kg (instrument and table)

Electrical: Voltage 100-260 VAC, 50-60 Hz

Nitrogen or CDA requirement
Pressure 0.55–0.9 MPa (80–130 psi)
Flow rate 40 L/s (85 cfm) minimum


Unfilter 24: 24-well plate, up to 8 mL per well, 10 kDa, regenerated cellulose
Unfilter 96: 96-well plate, up to 450 µL per well 3, 10, 30, 100 kDa, regenerated cellulose
Disposable tips 1000 µL non-filtered, automatic re-use up to 12 times per exchange

Dispense precision
<300 µL: ≤3 µL
0.3–8 mL: ≤1%