Selecting the most appropriate EFA (Effective Filtration Area) will maximize throughput and minimize filter changes. The greater the volume being filtered, the larger the filter diameter you should choose. However, one of the tradeoffs for a larger filter diameter is greater sample loss due to hold-up volume, or fluid retained in the filter.

Sample Volume	Device	EFA	Hold-up
< 5 mL	13 mm Acrodisc®	1.0 cm2	< 30 μL
5 – 100 mL	25 mm Acrodisc	2.8 cm2	< 70 μL
20 – 150 mL	32 mm Acrodisc	5.8 cm2	< 90 μL
100 mL – 5 L	AcroPak™ 20	20 cm2	< 2.5 mL
100 mL – 5 L	VacuCap® 60	30 cm2	< 3.4 mL
5 – 25 L	AcroPak 200	200 cm2	< 6 mL
10 L – 100 L	AcroPak 500	500 cm2	< 25 mL
10 L – 100 L	AcroPak 1000	1000 cm2	< 45 mL

Pall offers a range of membrane discs and devices to meet your specific filtration needs. Our liquid filtration membranes are available in configurations that process from > 5 mL to 100 liters. Choose from these membranes:

Direct Flow Filtration Membrane Selection

Membrane	Type	Characteristics
Supor®	Hydrophilic polyethersulfone (PES)	High flow rates and throughputs Low protein binding Extensive drug compatibility
Fluorodyne® II	Hydrophilic polyvinylidene fluoride (PVDF)	High flow rates Extremely low pressure drop Exceptional strength Low protein binding Low extractables Broad chemical and temperature resistance
Ultipor®	Nylon 6,6	Industry standard for pharmaceutical filtration Broad solvent and chemical compatibility Low extractables
Posidyne®	Positively-charged Nylon 6,6	Enhances bioburden and pyrogen removal from aqueous solutions
Versapor®	Acrylic copolymer on a nonwoven support	Designed for applications requiring excellent retention properties combined with tensile strengths in excess of 200 bar (3000 psi) Economical choice for clarification
HT Tuffryn®	Polysulfone	Low protein binding Durable and easy to handle

The more particulate-laden and/or the higher the protein concentration in a solution, the more difficult it is to filter. These types of liquids may clog filters prematurely and multiple filters may be needed to process single batches, increasing the cost of filtration. The most efficient way to filter these solutions is to choose a filter with a built-in prefilter or a filter with more filtration area (EFA = Effective Filtration Area). Pall Life Sciences can recommend an efficient filter for your toughest application needs.

Built-in Prefilter Enhances Throughput of Viscous, Particulate-laden or Proteinaceous Solutions

Serum-free media and buffers are typically not as challenging to filter as serum-containing media. However, it is common for protein concentrations to be very low in these solutions. With this in mind, it is very important to choose a low protein-binding syringe filter.

Binding is the property of substances to have an affinity for filter media or other filter components. When filtering solutions with low protein concentrations, certain filters can lead to the loss of active proteinaceous ingredients.

To minimize protein loss during filtration of proteinaceous solutions, choose our Supor membrane that exhibits low non-specific protein binding.

For process development applications, choose products from Pall's UpScale^SM Program. The UpScale Program offers the most comprehensive range of products to support your applications from drug discovery and basic research through process development and production. The UpScale Program product line includes a range of filtration devices with identical membranes and similar materials of construction to minimize any process variation due to filter changes when the processing volume increases. Count on Pall Corporation to provide you with scaleable filtration products and support your need to bring new products to market faster. For sterile filtration, choose Acrodisc® syringe filters and AcroPak™ capsules.

Even if all of the other components of your freezing media have been filter sterilized, DMSO can add contaminants that may not be detected until after the cells are removed from storage and thawed. Because DMSO is an aggressive solvent, many commonly used filter materials are unstable in DMSO. The DMSO-safe Acrodisc syringe filter can be used to filter-sterilize solutions containing DMSO to eliminate surprise contamination upon thawing cells.

Mycoplasma contamination in cell cultures can be difficult to detect. Most often, the only real solution is to discard all suspect cultures and reagents. Devices with 0.1 µm Supor membrane can be used for added assurance to filter liquids where the potential for mycoplasma contamination exists. This membrane is routinely tested for retention of mycoplasma (A. laidlawii). Pall's 0.1 µm Supor membrane devices are available in 25 and 32 mm Acrodisc syringe filters, AcroCap devices, AcroPak 20 devices, VacuCap devices, and AcroPak capsules.