M-Tech supplies a comprehensive range of membrane filtration equipment and consumables, from filter papers and filter membranes to vacuum manifolds and disposable filter monitors.
Membrane Filters
Products for Membrane Filtration
M-Tech supply a wide range of filtration equipment supplied by Advantec MFS. Membrane filters are microporous plastic films made from a variety of polymers. Since the commercial introduction of membrane filters 30 years ago, they have become widespread for use in industrial/process and research applications. The versatility and unique physiochemical properties of membrane filters have made ``membrane filters`` a common phrase.
Membrane filters, microporous filters, screen or sieve filters are all synonyms for filters with specific pore ratings which retain particles or microorganisms larger than their pore size by surface capture and some particles smaller than the stated pore size by other mechanisms. Such filters usually have a rated pore size within the range of 0.1-5µm. This type of filter is referred to as a membrane.
Advantec MFS membranes (with the exception of PTFE and PCTE) are reverse phase, solvent cast membranes. Here, controlled evaporation or removal of the complex solvent systems forms the porous structure. Reverse phase membranes are available in Nitrocellulose, Cellulose Acetate, Mixed Cellulose Esters and Nylon. PTFE membranes are made by a patented process where the membranes are stretched biaxially to form the porous structure.
Important performance characteristics of Advantec MFS membranes:
Thin, high porosity - Typically, a single layer of membrane is approximately 150µm thick with a porosity of approximately 80%. Pore ratings represent mean values around which there is a distribution of pores. These porous filters exhibit high liquid flow rates and high gas flow rates per unit area. In addition, one must consider there is a very high surface area available for selective adsorption or nonspecific binding.
Strength - Advantec MFS membranes are monitored for both burst (longitudinal) and tensile (lateral) strength. Supported Acetate and Nylon are the strongest reverse phase membranes are available from Advantec MFS, followed by Cellulose Acetate. All membranes will withstand autoclaving. Consult the specifications for more complete information.
Chemical and Biological Cleanliness - Membrane cleanliness is affected by the raw materials that are used in the manufacturing process, membrane treatments and by the way the membrane is handled after the casting operation. To assure membrane cleanliness, Advantec MFS uses only high purity reagents and raw materials. Once cast, the membranes are handled in a class 100 clean room to minimise ambient contamination. Some membranes will contain 0.1-3(wt%) of an aqueous wetting agent. Cellulose Acetate membranes have a lower aqueous extractable, 0.1(wt%), nitrocellulose the highest 3.0(wt%).
Thermostability - All Advantec MFS membranes can be sterilised by autoclaving. Advantec MFS membranes can be used over a broad range of temperatures. Cellulose Acetate membranes can withstand 130ºC, Nylon will withstand 180ºC. Specific maximum temperature limits can be found in the catalog (contact us for one). In addition, these membranes exhibit minimal shrinkage at elevated temperatures. Cellulose Acetate membranes should be pre-wet prior to loading then in the holder and autoclaving.
Choosing the correct membrane filter for your needs:
- Determine what liquid or gas will be filtered
- Determine the maximum pore size required to achieve the results you want
- Using the chemical compatibility chart, determine which polymer types are available
- Identify any unusual process conditions that would otherwise limit your choice of membrane
- Choose your preferred pack size
Disposable Filter Monitors
M-Tech supplies a range of sterile disposable filter monitors, which may be used to eliminate some of the time consuming activities associated with traditional filtration methods (such as sterilisation of filtration units, etc), manufactured in the US by BioPath Inc.
Disposable Filter Monitors are available pre-sterilised, removing the requirement of sterilising the filtration equipment, and eliminating any risk of cross contamination associated with transferring a membrane from a packet to a filter unit. The Disposable Filter Monitors are constructed with a removable funnel, allowing you run a 100ml sample, which may then be discarded after use.
Disposable Filter Monitors are available with a removable membrane allowing the membrane to be transferred to an agar plate for processing as traditional methods.
Available with White (nitrocellulose) and Black (mixed-ester) membranes in 0.2μm and 0.45μm pore size, 47mm or 56mm diameter fixed or removable membrane.
All Disposable Filter Monitors units have 100ml removable sample reservoir. The membrane is fixed in place for use with broth media. Surface area 25% greater than with a 47mm membrane.
NanoCeram® High Flow Rate Alumina Filters
For high flow rate filtration with 99.999% bacterial, viral and protozoa retention
NanoCeram® is a novel material developed by Argonide Corp. Orlando U.S.A. for the seperation of proteins and biological solutions. The unique NanoCeram filtration material retains 99.9999% protozoa such as Cryptosporidium (>5 logs), bacteria and viruses at flow rates more than 200 times greater than equivalent virus-rated filter membranes.
NanoCeram® has been shown to be highly effective in a wide variety of applications:
- Production of potable water
- Sterilisation of pharmaceuticals and medical sera
- Chromatography filtration of DNA/RNA and endotoxins
- Support matrix for bioengineering
- Collection of biowarfare agents
