Bottle-top vacuum filter selection guide
1) Select membrane material best for your application
Polyethersulfone (PES) membranes are highly recommended for filtering cell culture media. PES has both very low protein binding and extractables. PES also demonstrates faster flow rates than cellulosic or nylon membranes.
Cellulose acetate (CA) membranes have a very low binding affinity for most macromolecules and are especially recommended for applications requiring low protein binding, such as filtering culture media containing sera.
See Membrane technical tip below
Cellulose nitrate (CN) membranes are recommended for filtering solutions where protein binding is not a concern. They are recommended for use in general laboratory applications such as buffer filtration. Corning’s cellulose nitrate membranes are Triton X-100-free and noncytotoxic.
See Membrane technical tip below
Nylon membranes are naturally hydrophilic and are recommended for applications requiring very low extractables since they do not contain any wetting agents, detergents or surfactants. Their greater chemical resistance makes them better for filtering more aggressive solutions, such as alcohols and DMSO. However, like cellulose nitrate membranes, they may bind greater amounts of proteins and other macromolecules than do the cellulose acetate or PES membranes. They are recommended for filtering protein-free culture media.
Membrane technical tip – removing wetting agents
Both cellulose acetate (CA) and cellulose nitrate (CN) membranes are naturally hydrophobic and have small amounts (less than 1%) of non-toxic wetting agents added during manufacture to ensure proper wetting of the membrane. If desired, these agents can be easily removed prior to use by filtering a small amount of warm purified water through the membrane or filter unit.
2) Select membrane pore size
The pore size is usually determined by your application or objective.
Pore size (µm)
|
Applications
|
|
0.2 and 0.22 |
Routine laboratory sterilization of most media, buffers and biological fluids |
|
0.45 |
Clarification and prefiltration of solutions and solvents |
3) Select membrane diameter
Select a filter that will have enough volume capacity or throughput to process your entire sample quickly and efficiently. This is primarily determined by the effective surface area of the membrane.
The table below shows the relationship between filter diameter, effective filtration surface area and expected throughput volumes. The lower values are typical of viscous or particle-laden solutions; the higher values are typical of buffers or serum-free medium.
| Filter Diameter
|
Effective
Filter Area
(cm2
)
|
Expected
Throughput
(mL)*
|
|
50 mm vacuum system |
16.6 |
100 - 750
|
|
70 mm vacuum system
|
38.5
|
300 - 1500
|
|
90 mm vacuum system |
58.1
|
500 - 2000
|
*These values assume an aqueous solution and a 0.2 micron membrane. Solutions containing sera or other proteinaceous materials will be at the lower end of the range. Use of prefilters may extend the throughput 50-100% above the values shown.
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