Acupuncture needles might be the answer: If you turn the drop over, the the membrane is on top and the crystals hang off it. So you stick the needle into the membrane from the side, and gently poke the crystals so they fall off the membrane to the bottom. When you've knocked all of them down, you pull off the membrane (with the needle), and now you have free access to the crystals.
If you have sitting drops and crystals stick to the plastic, you can poke the needle into the plastic just below the crystal. This deforms the plastic and the crystal almost always pops off undamaged. Cheers Frank > -----Original Message----- > From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On > Behalf Of Edwin Pozharski > Sent: 07 March 2007 15:55 > To: [email protected] > Subject: Re: [ccp4bb] How to get rid of Membrane formed on > hanging droplets? > > I had some luck once cutting the crystal out of skin with a > razorblade. > When the skin is extremely sticky, you tend to get your > crystal wrapped up in it (which may be OK - you just get more > background scatter) and carefully cutting skin on all four > sides may be a better option. > > Wang, Yeming (NIH/NIEHS) [F] wrote: > > Dear everyone, > > > > I am working on crystallization of a protein/RNA complex > recently. The crystals were initially grown from BICINE(9.0) > 0.1M, 1,4-Dioxane 2%(v/v) , PEG 20,000 10%(w/v), at 10mg/ml. > I noticed that there was a membrane formed on the surface of > the hanging droplets. This membrane seems very sticky. > Consequently, almost all of the crystals stick to this > membrane and can't be seperated for data collection. Sitting > drops were also tried but crystals stick to the bottom of the > sitting well. Different buffer(Tris, CHES), different PEG(PEG > 8000, PEG3350, from 10%-1%) and different protein > concentration (10-3mg/ml) were also tried, but the sticky > membrane was still there. Does anyone have some experience > solving this problem? Any suggestions would be highly appreciated! > > > > Yeming > > --------------------- > > Yeming Wang, Ph.D. > > Laboratory of Structural Biology: Macromolecular Structure Group > > National Institute of Environmental Health Sciences > National Institute > > of Health > > Mailing Address: Street Address: > > NIEHS, MD F3-05 NIEHS, Building 101, Room F363 > > P.O. BOX 12233 111 T.W. Alexander Drive > > RTP, NC 27709 RTP, NC 27709 > > Tel (o): 919-316-4634 > > E-mail: [EMAIL PROTECTED] > > > > -- > Edwin Pozharski, PhD, Assistant Professor University of > Maryland, Baltimore > ---------------------------------------------- > When the Way is forgotten duty and justice appear; Then > knowledge and wisdom are born along with hypocrisy. > When harmonious relationships dissolve then respect and > devotion arise; When a nation falls to chaos then loyalty and > patriotism are born. > ------------------------------ / Lao Tse / >
