Syringe filters are single-use filtration devices that are made up of a membrane, or combination of membranes, placed inside molded housing. The connections on the device are commonly Luer lock or Luer slip and enable a quick connection to syringes, that are used to pass the liquid sample through the filter.
There are multiple membrane types, pore sizes, and housing material variants.
Syringe filters are chosen based upon suitability to a user's application. Syringe filters are typically split in five categories, based upon the user applications:
Syringe filters are typically single-use and should not be reused as syringe filter performance is based upon the first filtration. Reuse may negatively impact performance and sample results, due to causing cross-contamination, loss of sample, or blockage due to membrane fouling. However, reusable syringe filter holders are available that utilize replaceable membranes.
There are several methods of sterilization, such as gamma irradiation, e-beam, ethylene oxide gas exposure, and autoclaving. It is recommended to use devices pre-sterilized by the manufacturer if sterilization is required, to ensure performance and certified sterilization. Alternatively, some devices may be autoclaved in the lab, but this should be checked for each device.
Primary uses of syringe filters are the general clarification of particles from a liquid or air/gas samples, the sterile filtration of a sample to remove bacteria, the removal of particles and suspended solids prior to analytics such as HPLC. Syringe filters may also be used for gas venting, allowing clean, sterile air to pass through in vessels such as bioreactors.