Centrifugal Filter Devices Frequently Asked Questions
How do I Choose The Correct MWCO Filter?
For proteins, it is recommended that the selected MWCO is three to six times smaller than the molecular weight of the solute being retained. If flow rate is a consideration, choose a membrane with an MWCO at the lower end of this range (3X); if the main concern is retention, choose a tighter membrane (6X). Because different manufacturers use different molecules to define the MWCO of their membranes, it is important to perform pilot experiments to verify membrane performance in a particular application.
Can I Reuse MWCO Centrifugal Filters?
Although not ideal, MWCO filters can be reused if they don’t clog and provided that the proper cleaning protocol is followed. If there is a drastic protein loss or concentrating starts to take an unexpected long time, the filter is clogged. Despite this fact, they should be discarded after a maximum of three uses. These filters may start to leak after being used 2-3 times.
How do I Choose The Appropriate Centrifuge?
By using the proper rotor and adators to house your filtered tubes, it should be able to reach the G force required in your filtration protocol.
What is The "Reverse Spin" Technique and How do I Perform This?
In order to get all of your concentrated sample without using a pipette, you can reverse spin your concentrator. This is done by inverting the concentrator into a collection tube and centrifuging again in order to get all drops of your sample. This technique is perfect for samples that are difficult to concentrate or when the sample is concentrated to less than 50 µl.