Hi Aidong, I've seen this in protein samples that have been snap frozen then thawed on ice. Thawing at room temperature (or in the hand) stopped this state forming. Could temperature be the issue? Maybe try 10C or leave the samples on the bench for a while and see if the state is reversible?
David Hargreaves Associate Principal Scientist _____________________________________________________________________ AstraZeneca DECS, CP&SS Mereside, 50F49, Alderley Park, Cheshire, SK10 4TF Tel +44 (0)01625 518521 Fax +44 (0) 1625 232693 David.Hargreaves @astrazeneca.com Please consider the environment before printing this e-mail -------------------------------------------------------------------------- AstraZeneca UK Limited is a company incorporated in England and Wales with registered number: 03674842 and a registered office at 2 Kingdom Street, London, W2 6BD. Confidentiality Notice: This message is private and may contain confidential, proprietary and legally privileged information. If you have received this message in error, please notify us and remove it from your system and note that you must not copy, distribute or take any action in reliance on it. Any unauthorised use or disclosure of the contents of this message is not permitted and may be unlawful. Disclaimer: Email messages may be subject to delays, interception, non-delivery and unauthorised alterations. Therefore, information expressed in this message is not given or endorsed by AstraZeneca UK Limited unless otherwise notified by an authorised representative independent of this message. No contractual relationship is created by this message by any person unless specifically indicated by agreement in writing other than email. Monitoring: AstraZeneca UK Limited may monitor email traffic data and content for the purposes of the prevention and detection of crime, ensuring the security of our computer systems and checking Compliance with our Code of Conduct and Policies. -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of aidong Sent: 30 August 2011 16:31 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Protein preps become a jelly Dear Buddies, Sorry for bothering you with an off-ccp4 question. We recently are experiencing a very strange phenomena. A couple of protein preps with reasonably high concentration (10-20mg/ml) become a jelly after storages for overnight or a couple of days at 4C. All of them have been purified by gel filtration. Some of these proteins behave like this from very first preps but some of them had been very kind to us previously. We have googled extensively in CCP4BB and www but it appears this only happens to us. It would be highly appreciated that you could exchange their experiences or provide your suggestions. Aidong Han, Ph.D Department of Biomedical Sciences School of Life Sciences Xiamen University Xiamen, Fujian 361005 China Phone: 0592-218-8172 (O) 0592-218-8173 (L) Web: http://life.xmu.edu.cn/adhanlab/