Bottle-Top Vacuum Filter

What is the Bottle-Top Vacuum Filter?

A bottle-top vacuum filter is a large-area membrane unit that filters hundreds of millilitres into a storage bottle. It is used to prepare buffers and media or to sterilise solutions, with large membrane area for fast flow.

Overview

The unit combines a funnel, a membrane of 0.22 or 0.45 µm and a screw-on receiver bottle of 150 mL to 1 L. Vacuum applied to the receiver draws liquid through the membrane, which has a large effective area, typically 30–50 cm2, so filtration is fast compared with a syringe filter. Membranes are usually PES, cellulose acetate or PVDF for aqueous solutions, and the unit is provided sterile for media and buffer preparation, or non-sterile for particulate removal. The funnel may be removable, allowing the same filter to process several aliquots, and the receiver is graduated. These units are used in cell culture and microbiology for media sterilisation, in buffer preparation and in laboratories that filter litre volumes, and they reduce handling compared with repeated syringe filtration.

How does it work?

A laboratory filter separates particles from liquid by passing the liquid through a porous membrane with a defined pore size. Particles larger than the pore are retained on the surface or within the structure, while the filtrate passes through. Membrane material determines chemical compatibility and adsorption: PTFE is inert to most solvents and is used for organic mobile phases, PVDF suits aqueous and mixed phases, nylon binds proteins and is used where adsorption is not an issue, and cellulose acetate and PES are used for aqueous and biological solutions. Pore size of 0.45 µm removes most particulates, while 0.22 µm is used for sterilisation by filtration because it retains bacteria. The housing, whether polypropylene syringe filter, a bottle-top unit or a centrifugal device, provides the driving force and the connection. Extractables and hold-up volume are the main performance risks.

What are the key features?

• Large membrane area 30–50 cm2
• Pore size 0.22 or 0.45 µm
• Receiver bottle 150–1000 mL
• PES, CA or PVDF membrane
• Removable funnel option
• Sterile or non-sterile supply

What are the technical specifications?

A typical bottle-top vacuum filter configuration offers membrane area of 30–50 cm2, pore size of 0.22 or 0.45 µm, membrane of PES, CA or PVDF, receiver volume of 150–1000 mL, connection of Vacuum port and funnel of Fixed or removable. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Bottle-Top Vacuum Filter is used in media sterilisation, buffer preparation, solution clarification and cell culture reagents. Across the wider Filters class, laboratories also deploy it for sample clean-up before HPLC, mobile phase filtration and sterilisation by filtration.

Which standards and certifications apply?

Relevant standards and methods include USP <788> (particulate matter in injections), USP <665> (plastic components and systems), ISO 13485 (medical device quality management), ISO 10993 (biological evaluation of medical devices), EN ISO 11607 (packaging for terminally sterilized devices) and USP <1664> (assessment of drug product leachables). Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Pre-rinse the filter with the solvent or mobile phase when the method is sensitive, because membranes contain extractables such as wetting agents or oligomers that can appear as peaks, especially with LC-MS. Use a filter with a larger pore or a glass fibre prefilter for dirty samples, since a clogged 0.22 µm filter is a common cause of lost samples. Do not use the same filter for different samples if carry-over matters, and never filter a sterile solution into a non-sterile container. Check the pressure rating of syringe filters, because high pressure can burst the housing and release particles. Store filters in their packaging and respect expiry, especially for sterile units. Record lot numbers, since extractables and adsorption can vary between lots.

How do I select the right Bottle-Top Vacuum Filter?

Choose a bottle-top unit for volumes above about 100 mL, with the pore size and membrane suited to the solution. RFQ: volume, pore size, membrane, sterility and receiver size. Provide the volume and sterility needs required.

How does it compare with other Filters variants?

Choose the membrane by the solvent, the analyte and the purpose. Use PTFE for organic solvents and aggressive chemicals, PVDF or PES for aqueous and mixed phases, and cellulose acetate for aqueous solutions where low protein binding is wanted. Choose 0.22 µm for sterilisation or where microbes must be removed, and 0.45 µm for general particulate removal before chromatography. Match the format to the volume: syringe filters for 1–100 mL, bottle-top units for 100 mL to several litres, disc filters for vacuum or pressure holders, and centrifugal units for small volumes and concentration. Confirm the housing is compatible with the solvent, check hold-up volume for small samples, and ask for extractables data when the method is sensitive. Do not use a filter that adsorbs the analyte, and verify recovery with your compounds.