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Centrifugal concentrators - (Feb/23/2011 )


I'm a newbie at using centrifugal concentrators for concentrating proteins.
Can anyone provide me with a basic step by step procedure?
My protein is lac repressor FPLC purifed using a cation exchanger column(P11-Phosphocellulose)


Hola, These devices are as a net with a contolled pore. In your case to concentrate lac repressor of 38KD i would use a 10KD membrane better than 30KD because the limits arenīt exacts. Choose the device adecuated for your sample volume (You could refill some times) centrifuge under the supllier instuctions, store filtrate to analyze and when the retentate has a volume adecuated, mesure protein concentrations and thatīs all. Buena suerte


Basic procedure:
- add your sample to top container of the concentrator
- place in centrifuge and spin for certain amount of time (refer to instruction manual provided by the manufacturer)
- collect concentrated solution from the top container

Open this link: Amicon Ultra-15 Centrifugal Filter Units - then pick "User Guides" on the right (Related Resources section), then "Amicon Ultra-15 Centrifugal Filter Devices User Guide", then open PDF.


Thanks a lot guys! Much appreciated.
By the way, does anyone know how best to store the Lac repressor after centrifugal concentration?


These filtration units are a touch on the expensive side, and while I don't use them for proteins, my colleagues that use them for protein work, clean and reuse the tubes a few times before tossing them out.