Best Membrane Filters for Lab Filtration: How to Pick the Right One
When it comes to laboratory filtration, choosing the right membrane filter can significantly impact the accuracy, speed, and success of your experiments. With so many types, materials, pore sizes, and applications, the decision can be overwhelming — but it doesn’t have to be.
In this guide, we break it down step by step so you can make the right choice for your specific application.
Step 1: Know Your Application
The first and most important step is to understand what you’re filtering.
| Application Type | Considerations |
| Sample clarification | Look for high flow rate, low protein binding |
| Sterilization | Use 0.22 μm pore size; choose appropriate material |
| Particulate analysis | Use black or gridded filters for visibility |
| Gas filtration | Use hydrophobic membranes like PTFE |
| Protein solutions | Choose low protein-binding membranes (e.g., PVDF) |
Step 2: Choose the Right Pore Size
| Pore Size (μm) | Best For |
| 0.1 μm | Mycoplasma removal |
| 0.22 μm | Sterile filtration (bacteria removal) |
| 0.45 μm | General clarification |
| 1.0 μm+ | Particle removal, pre-filtration |
Pro Tip: If your solution is viscous or contains a lot of particulates, pre-filter with a 0.8–1.2 μm membrane before using a 0.22 μm filter.
Step 3: Select the Right Membrane Material
| Material | Properties | Best For |
| PTFE (Polytetrafluoroethylene) | Hydrophobic, chemically resistant | Gas filtration, aggressive solvents |
| PES (Polyethersulfone) | Hydrophilic, fast flow, low protein binding | Cell culture, protein filtration |
| PVDF (Polyvinylidene fluoride) | Low protein binding, strong | Biological samples, alcohol-based solutions |
| Nylon | Hydrophilic, high strength | Aqueous and organic samples |
| Cellulose Acetate | Low protein binding | Enzyme and protein solutions |
| MCE (Mixed Cellulose Esters) | High flow, good retention | Microbiology, particulate analysis |
Step 4: Consider Hydrophilic vs. Hydrophobic
- Hydrophilic membranes: Ideal for aqueous solutions
- Hydrophobic membranes: Ideal for gases and non-polar solvents
If filtering an aqueous solution with a hydrophobic membrane, you’ll need to pre-wet it with alcohol or another miscible fluid.
Step 5: Select Format and Size
- Disc filters: Used in syringe filter housings or filtration assemblies
- Syringe filters: Convenient for small volumes (≤200 mL)
- Diameter:
- 13 mm: Up to 10 mL samples
- 25 mm: 10–100 mL
- 33 mm: >100 mL
Common Mistakes to Avoid
- ❌ Using a membrane with poor chemical compatibility (it may degrade or block)
- ❌ Wrong pore size (risk of losing particles or contamination)
- ❌ Using hydrophobic filter for water (flow may be blocked)
- ❌ Not pre-wetting hydrophobic membranes when needed
Still Not Sure?
We’re here to help! At Reactivo, we supply high-quality membrane filters in a variety of sizes and materials. If you’re unsure, contact us and we’ll recommend the right product based on your application.
Need help choosing? Contact Us or try our Filter Finder Tool.
Conclusion
Choosing the right membrane filter doesn’t have to be complex. Just remember to:
- Understand your application
- Match pore size and material accordingly
- Consider hydrophilic vs. hydrophobic
- Select the right size and format
Still have questions? Reach out to our support team or browse our catalogue.
