Presentation on theme: "Membrane Filtration - Ahlstrom Brand – ReliaDisc and ReliaPrep - Sartorius Original Cornelia Wiegand."— Presentation transcript:
1 Membrane Filtration - Ahlstrom Brand – ReliaDisc and ReliaPrep - Sartorius Original Cornelia Wiegand
2 Ahlstrom ReliaDiscTM Membranes Gridded sterile nitrocellulose membranes for use in colony counting and microbiological quality control.Non-sterile microfiltration membranes used to remove particles and microorganisms from organic solvents (PA, PTFE, RC) and aqueous solutions (CA, CN).Ahlstrom ReliaPrepTM Syringe FiltersWide variety of highest quality syringe filters for convenient sample preparation and fluid sterilization.CA and PES membranes recommended for aqueous solutions filtration; PA, PTFE and RC membranes recommended for organic solvent filtration.Many references available on special order.
4 Filter Types Depth Filters Filter papers are mostly made of cellulose and are characterised by high absorbency.They have high particle retention capacity and allow a large sample throughput.
5 Depth FilterThe filter matrix consists of a three-dimensional network of fibres.Retention of particles and micro organisms mainly in the "depth" of the filter matrix by mechanical retention and adsorption.Advantage: High particle holding capacity without premature clogging.The nominal retention rate is especially influenced by the diameter of the fibres, the "compactness" of the fibre structure, and the thickness of the filter.
7 Membrane Filters are relatively thin and made of synthetic polymers. Filter TypesSurface FiltersMembrane Filters are relatively thin and made of synthetic polymers.They are used for the filtration of fine particles or the collection of micro- organisms.
8 Surface FilterThe filter matrix consists of a homogeneous "sponge-like" pore structure of high mechanical stability and pressure resistanceRetention of particles and micro organisms is mainly "on or near the surface of the“ filter matrix by mechanical means.Advantage: High safety against breakthrough even at high differential pressures and pressure surges.
10 1 µm = 0.001 mm = 0.000001m Scale of Dimensions 100 µm monkey hair µm smallest particle you can seeµm yeast bacteriaµm virus
11 Cellulose Acetate (CA) High flow ratesLow affinity for proteinRoutinely used to filter protein solutionse.g. Fetal calf serum (FCS) Bovine serum Albumin (BSA)Good resistance to certain solventsManufactured without surfactant (SFCA)Good handling, especially when wetAutoclavablePore size 0.2 ; 0.45: 0.65 ; 0.8; 1.2; 5 µm
12 Regenerated Cellulose (RC) For ultra cleaning and de-gasing solvents and mobile phase for HPLCSolvent-resistant hydrophilicmembrane - Particle removal of solvents - Low non-specific adsorption - Good handling- Pore size 0.2 and 0.45µmPage 9
13 How to convert to RC Chemical compatibility Flow rates Non-specific bindingThermal stabilityPage 10
14 Minimizing Extractables What can cause extractables- Solubility and chemical compatibility- Particle displacementWhy reduce extractables?How do you reduceextractables?HPLC certificationIncrease accuracy by removing unwanted particlesCompatibility tested with commons solventsPage 11
15 Polyamide (NY)Relatively slow to moderate flow rate due to low porosity and membrane thickness ( µm) - Excellent solvent resistance (Ideal for HPLC) - No surfactant required - Very low level of extractables - High non-specific affinity for proteins. - Used as an alternative to CN for blotting - Not recommended for filtering proteins e.g FCS and BSA - Autoclavable - Pore size 0.2 and 0.45µmPage 12
16 Polyethersulphone (PES) Fast flow ratesLow extractablesLow protein bindingGood solvent resistanceAutoclavableGood membrane for FCSPore size 0.1; 0.2 and 0.45µmPage 13
17 Polytetrafluoroethylene (PTFE) PTFE is very low protein bindingHas good to moderate flow ratePTFE resistant to all known solventsPTFE is hydrophobicUsed for venting applicationsPore size 0.2 ; 0.45 ; 1.2 and 5µmPage 14
18 Membrane FiltrationSterile filtration and ultra cleaning of liquids => 0.2µmParticulate removal of liquids, micro-biological reduction filtration and particulate removal of dry air and gases => 0.45µm and 0.8µmClarification and pre-filtration => 1.2µm and 5.0µm
19 Membrane filtration has to become supported either by vacuum or by pressure Disc Filters and DisposablesDisc membrane filtersused in a disc deviceautoclavable deviceReady to use filtershave integrated membranessmal hold-up volumesavailable sterile or non-sterile
20 Vacuum glass filter holder For disc membranesSize diameter 13mm and 47/50mm
21 Syringe filters / CArapid clarification or sterilization of up to 100 ml liquid volumeslow unspecific adsorptionfitted to a dosing syringe makes a very convenient systemfor dosing and sterilizingdifferent pore size membrane filters => colour coded0.45, 0.8, 1.2, 5.0 can be mounted directly in front of an 0.2 µm syringe filterPage 15
22 Syringe Filter Housing MBS (methacrylate butadiene styrene polymerisate or Cryolite)Similr to Plexiglas – good tensile strength and impact strengthNon-autoclavable. Can be Gi or EtO sterilizedLimited thermal resistancepH rangePP polypropyleneCan be autoclaved or EtO sterilizedOutstanding chemical compatibilityLow extractablespH range 1-14
23 Syringe Filters, Application Overview Recommended ApplicationSterile FiltrationRemoval of microorganisms from solutions with ≤0.2um hydrophilic syringe filters: PES/CA/RC/NylonClarification/Pre-filtrationThe pre-filtration and purification of liquids with ≥0.45um hydrophilicsyringe filtersChromatography-sample prepUltra cleaning of small volume samples with chemical resistant syringe filters: RC/Nylon/PTFESterileventingRemoval of microorganisms from gasses and air with hydrophobic 0.2um syringe filters: PTFEMedical ApplicationsCA syringe filters for use in hospitals and pharmacies.Page 28
24 Volume / Diameter Volume to filter Aqueous solution, solvents Aggressive solutionUp to 1 mlRC 4 mmPTFE 4mmUp to 5 mlRC 15 mmPTFE 15 mmUp to 100 mlRC,25 mmPTFE 25 mm