Centrifugal concentrators - (Feb/23/2011 )

Hi!

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 aren´t 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 that´s 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.