Another approach is to use the microbatch-under-oil crystallization method - you very rarely get skins with that. Harvesting crystals from under oil is roughly as easy as from vapor diffusion drops. You have to make sure that the crystal fits the loop well, because it can be pulled off by the oil. On the other hand, you can take your time because you don't need to worry about evaporation, which makes it easier.
On Thu, Dec 4, 2025 at 7:22 AM Cesar Luna-Chavez < [email protected]> wrote: > 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 > -- [email protected] Douglas Instruments Ltd. Douglas House, East Garston, Hungerford, Berkshire, RG17 7HD, UK Directors: Patrick Shaw Stewart, Peter Baldock, Stefan Kolek http://www.douglas.co.uk Tel: 44 (0) 148-864-9090 US toll-free 1-877-225-2034 Regd. England 2177994, VAT Reg. GB 480 7371 36 ######################################################################## 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/
