Laboratory Filtration Systems

The choice follows the volume, the fluid and the goal of the step. Vacuum suits clarifying and sterilising modest bench volumes, pressure handles viscous or larger loads, and tangential flow concentrates proteins without clogging. Dead end methods filter to waste or capture, while crossflow recirculates to concentrate. Describe your volume and aim to the seller so they can confirm the right format.

Pore size sets what the membrane removes, from clarifying grades that catch cells and debris to sterilising grades that retain microbes. The membrane material must also resist your fluid without leaching or binding your target. Match both to the step you are doing. Ask the seller which membranes the holder accepts so the right grade and material fit.

Check the holder seals, the vessel integrity and any pump or gauge that comes with the rig. Worn seals leak and let unfiltered fluid bypass the membrane, which defeats the step. For tangential flow, ask about the pump and the condition of any installed membrane cassette. A rig with sound seals and a clear history is ready to use.

Tangential flow filtration concentrates proteins gently because the fluid flows across the membrane rather than being forced through it, which limits fouling and shear. Choosing the right membrane cut off retains your protein while letting buffer and small molecules pass. Run at a moderate pressure to protect fragile targets. The seller can confirm the membrane cut off and the pump on the listed system.

You deal with the seller straight through the listing, without a go between, arranging the sale and any inspection. Ask for photos of the holders and seals and a video of the rig running if it helps. Filtration sellers are vetted, which reinforces the exchange. Settle the terms before finalising the filtration purchase.