Vent Filters with PTFE Membranes

Yes, the presterilized syringe filters may be used after passing their expiration date.  However, we cannot guarantee that the filters are still sterile in the packaging.  For applications that are sensitive to microbial contamination, the expired filters should be chemically sterilized, or gamma sterilized, prior to use.  The expiration date only applies to filter sterility and is not relevant to filter performance.  If stored sealed in their original packaging in climate controlled environments, it is expected that expired filters will have normal flow and retention characteristics.

Yes, for water and some aqueous solutions, a hydrophobic membrane syringe filter installed in the tubing between the vacuum pump and the receiving flask can prevent accidental overflows from reaching the vacuum pump.  Sterlitech recommends PTFEVS4550BAR10 (https://www.sterlitech.com/ptfevs4565bar10.html) for this application.  Please note that this method will not work for low surface tension fluids, such as alcohols and solvents.

No, syringes are not included with syringe filters orders. We may be able to offer syringes separately; please contact [email protected] for pricing and availability. 

The syringe filter area, and other specifications, are readily available at www.sterlitech.com. Please go to the product page for your syringe filter and click the “Application/Specification” tab near the middle of the page. You can read the filter area from this tab; make sure to scroll down as necessary. Please contact [email protected] if you need assistance.

No, the syringe filter size refers to the nominal diameter of the disk filter contained within. Necessarily, the outer diameter of the housing is somewhat larger than the labeled size. For example, the 25mm presterilized syringe filters offered by Sterlitech have a housing outer diameter of 33mm.

The maximum recommended operating temperature for the syringe filters when used with compatible fluids is 60°C. When operating at high temperatures, the housing strength is reduced and it may be necessary to limit the applied pressure. Appropriate safety precautions, such as the use of personal protective equipment (PPE), should be used when working with hot fluids.

From our standard offering, the nylon membrane syringe filters (https://www.sterlitech.com/nylon-syringe-filters.html) have the smallest pore size rating available at 0.1µm.

Sterlitech can provide custom syringe filters (https://www.sterlitech.com/custom-syringe-filters.html) with pore size ratings down to 0.05µm.  Please contact [email protected] to inquire about availability and pricing.

The standard Sterlitech syringe filters that are 30mm in size or smaller have female luer lock inlet connection and male luer slip outlet connection. For customers that require different connections, Sterlitech offers custom syringe filters with a variety of connection options for your convenience at https://www.sterlitech.com/custom-syringe-filters.html. Please contact [email protected] to inquire about availability and pricing.

From our standard offering, the largest pore size rating available is 5 microns.  Both cellulose acetate (https://www.sterlitech.com/cellulose-acetate-syringe-filters.html) and nylon (https://www.sterlitech.com/nylon-syringe-filters.html) membrane syringe filters are available with 5 micron pore size rating.

Sterlitech can provide custom syringe filters (https://www.sterlitech.com/custom-syringe-filters.html) with pore size ratings up to 250 microns.  Please contact [email protected] to inquire about availability and pricing.

Yes, some of the syringe filters offer by Sterlitech may be autoclave sterlized. The exceptions are syringe filters with mixed cellulose esters (MCE) membrane and syringe filters with acrylic housings.

The syringe filters are primarily intended for laboratory use.  The syringe filters maybe evaluated for pharmaceutical applications; however, it would be the responsibility of the user to comply with all pertinent regulations.  Please contact [email protected] if you need assistance. 

Most of the syringe filters offered by Sterlitech do not contain surfactants.  The exceptions are syringe filters with cellulose acetate (CA) and mixed cellulose esters (MCE) membranes.  CA and MCE membranes are treated with surfactants to ensure good wettability.    

Q. Are Sterlitech Syringe Filters certified pyrogen free?

A. No, we do not perform pyrogen tests on our filters.

Q.  What are the maximum filtration volumes for the 17mm and 30mm syringe filters?

A.  The 17mm and 30mm syringe filters offer greater filtration volume than smaller filters.

• 17 - 12ml
• 17 with glass fiber prefilter - 20ml
• 30 - 120ml
• 30 with glass fiber prefilter - 180ml

The standard Sterlitech sterile syringe filters are sterilized by controlled exposure to gamma irradiation. The amount of irradiation is carefully controlled to ensure a sufficient dose for sterility. The effectiveness of the treatment is monitored for each lot by using strategically placed spore strips and sterility is confirmed before a lot is released for sale.

The glass fiber prefilter reduces the particle loading experienced by the membrane final filter and, consequently, extends the service life. For some applications with fluids containing high levels of suspended solids, a syringe filter with an incorporated glass fiber prefilter will usually have greater total throughput when comparted to one without a prefilter.

Because of their low inherent levels of extractables, nylon membrane syringe filters are commonly used to filter samples that are intended for HPLC analysis. Nylon membrane syringe filters may not be suitable for all samples and are ideal for near neutral pH aqueous solutions and compatible nonaqueous solvents. For samples composed of acids and bases, hydrophilic PTFE membrane syringe filters and PES membrane syringe filters may be considered. For samples composed of nonaqueous solvents that are not compatible with nylon, PTFE membrane syringe filters and polypropylene membrane syringe filters may be considered. For aqueous samples containing proteins, or similar large organic molecules of interest, syringe filters containing membranes with low inherent protein binding characteristics, such as cellulose acetate (CA), should be considered to ensure maximum recovery.

It would be expected that syringe filters containing absolute rated membrane media would be approximately equivalent regardless of supplier for filters that have the same size, same membrane material and same pore size rating. This is not the case for syringe filters containing nominally rated media such as glass fiber or nonwoven polypropylene. When considering alternative suppliers for nominally rated syringe filters, the user cannot typically rely on pore size rating alone. A more careful consideration of the media specifications, if available from the supplier, can help inform selection.

Yes, we can provide certificates of conformance (CoC) with syringe filter orders. Please make sure to the request the certificate when placing your order.