No real need, some folks do it like that. However, you'll need to fish out your protein from more junk and you may have more proteolytic degradation. Also, you will need more detergent compared to "membrane-only" extraction, especially when using mild detergents.
bert ________________________________________ From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Theresa Hsu [theresah...@live.com] Sent: Monday, January 06, 2014 9:56 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Membrane fractionation Dear crystallographers When we purify membrane proteins, we often fractionate the E. coli cell membrane by ultracentrifugation. Is there a need for this step instead of solubilizing the whole cell with detergents? Thank you. Theresa
