What filter should I use for aqueous samples?
The short answer: a hydrophilic membrane—PES, nylon, or hydrophilic-treated PVDF—at a pore size matched to your actual requirement.
Quick answer
PES is the common default for aqueous and biological samples—hydrophilic, low protein binding, fast flow. Nylon is a solid alternative, especially if some organic solvent is mixed in, as long as your analyte doesn't bind to it. Avoid standard (untreated) PTFE or PVDF unless you're using a hydrophilic-treated variant—they won't wet with water.
Pore size
0.22 µm for sterilizing-grade work, 0.45 µm for general clarification—see our pore size guide for the fuller picture.
For the full material comparison, see PTFE vs. nylon vs. PES vs. PVDF.
Need a more specific recommendation?
Tell us your exact sample and instrument, and we'll confirm the right spec.