How to Choose the Right Syringe Filter
Choosing a syringe filter shouldn't feel complicated. Once you know your sample and
your goal, it usually comes down to four simple decisions: membrane material, pore size, diameter, and sterility. Here's how we'd walk you through it.
1. Start with Your Sample: Membrane Material
The membrane is what actually touches your sample, so this is the decision that matters most. Pick a material that's chemically compatible with your solution to avoid extractables or unwanted interactions.
Nylon – Low extractables, works well with both aqueous and organic solvents. A common choice for clarifying samples before HPLC.
PES (Polyethersulfone) – High flow rate with low protein binding, ideal for aqueous and mildly organic solutions, including cell culture media.
PVDF – Naturally low protein binding, a strong option for protein-based or biological samples.
PTFE – Outstanding chemical resistance, suited for strong acids, strong bases, and harsh solvents.
MCE (Mixed Cellulose Ester) – High throughput, general-purpose filtration for aqueous samples.
CA (Cellulose Acetate) – Very low protein binding and high flow rate, a gentle option for protein solutions and biological samples where sample recovery matters.
RC (Regenerated Cellulose) – Naturally low in extractables and broadly solvent-compatible, making it a reliable choice for HPLC samples run in both aqueous and organic mobile phases.
Glass Fiber – Excellent for high-particulate or viscous samples that would otherwise clog a membrane filter, often used as a pre-filter layer.
At FINETECH we manufacture all of these membranes in both hydrophilic and hydrophobic versions, so once you've picked your material, there's one more decision to make below.
At FINETECH we manufacture across all of these membranes in-house, so if you're not sure which one fits your application, our team is happy to recommend one based on your sample chemistry.
2. Hydrophilic or Hydrophobic?
Every membrane we make at FINETECH is available in both versions, so this is worth its own step.
Hydrophilic membranes wet naturally with water and are the right choice for aqueous samples, buffers, and most standard laboratory solutions — no pre-wetting needed.
Hydrophobic membranes repel water and are built for organic solvents, air/gas venting, and applications where moisture needs to be kept out. If you're filtering an aqueous sample through a hydrophobic membrane, it will need to be pre-wet first, usually with methanol or isopropanol.
As a rule of thumb: if your sample is water-based, go hydrophilic; if it's a strong organic solvent or you're filtering gas or air, go hydrophobic.
3. Match the Pore Size to What You're Removing
The rule of thumb: pick a pore size smaller than the particles you need out of your sample.
0.1 µm – mycoplasma removal
0.22 µm – sterile filtration and bacteria removal
0.45 µm – general clarification and sample prep before analysis
0.8 µm and above – coarse pre-filtration for particulate-heavy samples
0.22 µm and 0.45 µm cover the large majority of laboratory use cases, which is why they're our most requested pore sizes across every membrane type.
4. Choose a Diameter That Fits Your Sample Volume
Filter diameter determines how much sample you can push through comfortably and how much liquid stays trapped in the filter (the hold-up volume). As a general guide:
Sample Volume | Recommended Diameter |
1–10 mL | 13 mm |
5–100 mL | 25 mL |
10–200 mL | 33 mm |
Smaller diameters minimize dead volume, which matters when every drop of sample counts — something we hear often from HPLC and LC-MS labs working with limited sample sizes.
5. Decide on Sterility
Sterile, individually packed filters are the right call whenever the filtered output needs to stay sterile — cell culture media, buffers, or any downstream sterile process.
Non-sterile, bulk-packed filters are a practical, cost-effective option for routine sample prep, especially when the sample will be filtered again or used in non-sterile analytical work.
A Quick Way to Remember It
Think of it as sample, water-compatibility, task, volume, then sterility:
What's my sample made of? → membrane material
Is my sample water-based or solvent-based? → hydrophilic vs. hydrophobic
What am I trying to remove? → pore size
How much am I filtering? → diameter
Does the output need to stay sterile? → sterile vs. non-sterile
A quick look at how our syringe filters are manufactured and how each membrane performs during filtration, a good starting point if you're new to our product line.
A closer look at our PureTech™, StarTech™, and MeTech™ ranges, including membrane options, color coding, and packaging formats available for each.
Still Not Sure Which Filter You Need?
That's exactly what our team is here for. With over 25 years manufacturing filtration products for laboratories in more than 45 countries, we can help you match the right membrane, pore size, and format to your exact application — including custom OEM configurations if your workflow calls for it.
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