BTW. How come nobody has asked about the crystallization conditions? I spent nearly four years nailing down the conditions to crystallize Fumarate Reductase from E coli. Certainly, I came across "skins" but managed to let the improvements lead me to a more conclusive protocol.
1) https://www.ucsf.edu/news/1999/06/97513/sfvamc-ucsf-scientists-solve-key-protein-structure 2) https://www.sciencedirect.com/science/article/abs/pii/S1046592800912385 3) https://journals.iucr.org/paper?cy0109 Feel free to reach out to start optimizing YOUR conditions to avoid skins. On Mon, Oct 6, 2025 at 5:19 AM Nichols, Charlie < [email protected]> wrote: > Hi, I have been offline for medical reasons for a few weeks… > > > > Trawling through my ~1000 emails and saw this thread… > > > > Have faced this problem many times, some crystals seem to like to grow > from the interface of skin and solution phase and are therefore inherently > adherent to the skin. > > > > Adding additives to stop skin formation changes the dynamics of vapour > equilibration and may be removing the preferred nucleation surface, which > can then reduce crystal quality rather than improving it e.g. either no > crystals or a tendency to obtain showers of smaller crystals. You may be > able to ameliorate this by using larger drops with lower surface area : > volume ratio and serial dilution of seeds, you may then find conditions > that give more good crystals not entrained with the skin. > > > > Re-solubilising the skin after crystal growth is however often the > simplest approach. For this I can recommend testing the Cryosol screen from > Molecular Dimensions, these multi-component organic solvent mixtures are > both excellent for cryoprotection and also very good at resolubilising skin > from PEG system crystallisations. > > https://moleculardimensions.com/en/category/cryoprotectant-screens > > > > Good luck, take care, > > Dr Charlie Nichols > > Charles River Laboratories > > > > *From:* CCP4 bulletin board <[email protected]> *On Behalf Of *amit > gaur > *Sent:* 16 September 2025 21:58 > *To:* [email protected] > *Subject:* [ccp4bb] Skin around crystal > > > > *WARNING: This message was sent by an external party. Report suspicious > messages via the “Report Phishing” button in Outlook.* > > > > Hi everyone, > > > > I am facing a problem during crystal freezing. My crystals are surrounded > by skin and not separating from skin during crystal mounting. It seems that > crystals are embedded in the skin. Has anyone experienced a similar > situation and handled this situation? > > > > *Dr. Amit Gaur, * > > *Department of Biomedical Science,* > > *College of Medicine,* > > *Florida State University,* > > *1115 W Call St, Tallahassee, FL,32304* > > > > > > > > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
