Syringe Filters FAQ

Yes. Expired presterilized syringe filters can still be used, but sterility is no longer guaranteed after the expiration date. The expiration date applies only to the sterility of the packaged filter, not to its filtration performance. When stored sealed in their original packaging under appropriate environmental conditions, the filters are expected to maintain their normal flow rate and particle retention. For applications requiring sterility, expired filters should be resterilized (e.g., by gamma irradiation or an appropriate validated sterilization method) before use.

Yes. A hydrophobic syringe filter installed between the vacuum pump and the receiving flask can help prevent accidental overflow of water and aqueous solutions into the pump. Sterlitech recommends the PTFEVS4550BAR10 PTFE syringe filter for this application. This method is not suitable for low surface tension liquids, such as alcohols or organic solvents, which can pass through hydrophobic membranes.

No. Syringes are not included with Sterlitech syringe filter orders. If you also need compatible syringes, they may be purchased separately. Please contact [email protected] for current pricing and availability.

The filtration area of each Sterlitech syringe filter is listed on its product page at Sterlitech.com. Simply navigate to your syringe filter product, select the Application/Specification tab, and scroll to view the complete specifications, including the effective filtration area. If you need help identifying the correct filter or locating the specifications, please contact [email protected].

No. The syringe filter size refers to the nominal diameter of the membrane filter inside the housing, not the housing's outer diameter. Because the housing encloses the membrane, its outside diameter is larger than the labeled filter size. For example, a 25 mm syringe filter has an outer housing diameter of approximately 33 mm.

The maximum recommended operating temperature for Sterlitech syringe filters is 60°C when used with compatible fluids. At elevated temperatures, the filter housing becomes less resistant to pressure, so the applied pressure may need to be reduced. When filtering hot liquids, always follow appropriate safety practices and wear suitable personal protective equipment (PPE). Note: This operating temperature applies to filtration use. Certain syringe filter models with polypropylene housings are autoclavable and can tolerate higher temperatures during sterilization.

The smallest standard syringe filter pore size offered by Sterlitech is 0.1 µm, available in Nylon membrane syringe filters. For applications requiring finer filtration, Sterlitech can provide custom syringe filters with pore sizes down to 0.05 µm, subject to availability. Please contact [email protected] to discuss your application and request pricing.

Standard Sterlitech syringe filters (30 mm and smaller) feature a female Luer lock inlet and a male Luer slip outlet, making them compatible with most standard laboratory syringes. If your application requires a different connection type, custom syringe filters are available with a variety of inlet and outlet configurations. Please contact [email protected] for availability, pricing, and custom options.

The largest standard syringe filter pore size offered by Sterlitech is 5 µm, available with both Cellulose Acetate (CA) and Nylon membrane syringe filters. For specialized applications, Sterlitech also offers custom syringe filters with pore sizes up to 250 µm, subject to availability. Please contact [email protected] to discuss your application and request pricing.

Yes. Many Sterlitech syringe filters can be autoclave sterilized. However, syringe filters with Mixed Cellulose Esters (MCE) membranes and those with acrylic housings are not suitable for autoclaving. Always verify the material compatibility before sterilization.

Sterlitech syringe filters are primarily designed for laboratory filtration applications. While they may be evaluated for pharmaceutical applications, it is the user's responsibility to determine suitability and ensure compliance with all applicable regulatory requirements and validation standards. If you need assistance selecting a syringe filter for your application, please contact [email protected].

Most Sterlitech syringe filters are surfactant-free. The exceptions are syringe filters with cellulose acetate (CA) and mixed cellulose ester (MCE) membranes, which are treated with surfactants to improve membrane wettability and ensure rapid liquid flow. If your application requires surfactant-free filtration, consider using alternative membrane materials such as PTFE, PES, PVDF, nylon, or polycarbonate, depending on your compatibility requirements.

No. Sterlitech syringe filters are not certified pyrogen-free, and pyrogen (endotoxin) testing is not performed on these products. If your application requires pyrogen-free, endotoxin-tested, or endotoxin-certified syringe filters, you should select filtration products that are specifically validated and labeled for those requirements.

The recommended maximum filtration volume depends on the syringe filter size and whether it includes a glass fiber prefilter: Syringe Filter Maximum Filtration Volume 17 mm Up to 12 mL 17 mm with glass fiber prefilter Up to 20 mL 30 mm Up to 120 mL 30 mm with glass fiber prefilter Up to 180 mL Actual throughput may vary depending on the sample viscosity, particulate load, and membrane type.

Sterlitech 17 mm and 30 mm syringe filters feature a durable polypropylene (PP) housing with a maximum operating temperature of 180°C. Unlike acrylic-housed syringe filters, the polypropylene construction offers greater heat resistance, and the filters are autoclavable for sterilization.

Sterlitech sterile syringe filters are sterilized using controlled gamma irradiation. The irradiation dose is carefully validated to achieve the required Sterility Assurance Level (SAL) without compromising filter performance. To verify sterility, each production lot is monitored using biological indicators (spore strips) during the sterilization process. Sterility is confirmed before the lot is released for sale.

A glass fiber prefilter captures larger particles before they reach the final membrane filter, reducing membrane fouling and extending filter life. For samples with high particulate loads or suspended solids, syringe filters with glass fiber prefilters provide higher total throughput, faster filtration, and improved overall filtration performance compared to filters without a prefilter.

The best HPLC syringe filter depends on your sample: Nylon: Ideal for most neutral aqueous solutions and compatible organic solvents due to low extractables. Hydrophilic PTFE or PES: Recommended for acidic or basic samples. PTFE or Polypropylene (PP): Best for organic solvents that are not compatible with nylon. Cellulose Acetate (CA): Ideal for protein-containing aqueous samples because of its low protein-binding properties, maximizing analyte recovery. Selecting the appropriate syringe filter membrane helps ensure optimal HPLC performance, sample recovery, and column protection.

It depends on the membrane media. Syringe filters with absolute-rated membrane filters of the same membrane material, pore size, and filter size generally provide comparable filtration performance across suppliers. However, nominally rated syringe filters, such as those containing glass fiber or nonwoven polypropylene, are not necessarily equivalent. For these filters, factors beyond pore size—such as media construction and performance specifications—should be evaluated when selecting an alternative supplier.

Yes. Sterlitech can provide a Certificate of Conformance (CoC) for syringe filter orders. To ensure the certificate is included, please request the CoC when placing your order.