Suggestions so far have been good ones. However, the MiTeGen microtools kit:
http://mitegen.com/products/microtools/microtools_kit1.shtml

comes with a "MicroSaw", which is a 10-micron thick kapton saw that is 
intended for this purpose. That is, you don't pry the crystal off the 
surface, but rather rest this saw against the surface, bring it over to 
the edge of the stuck crystal and then work it back and forth until you 
have cut underneath the crystal. Did you try this tool?

-James Holton
MAD Scientist


Savvas Savvides wrote:
>
> Dear colleagues,
>
> we have been growing crystals of a protein complex in sitting-drop 
> geometry that stick to the bottom of the drop remarkably well. It’s as 
> if they are glued onto the plastic. This makes crystal handling next 
> to impossible without destroying the crystals. We have tried whiskers, 
> loops, all kinds of micro-tools, and pipetting techniques to no avail. 
> I can say at the outset that we have been unsuccessful in growing 
> these crystals in hanging-drops or at 4 degrees. Deglycosylating the 
> complex also leads to nowhere. In fact, we are only able to get 
> crystals from homogeneously glycosylated protein produced in 
> HEK293S/I- cells.
>
> In the meantime we are playing with the idea of siliconizing the 
> sitting-drop depressions to alter the crystal/plate interface. But 
> then again, nucleation events on the plastic may be the reason we are 
> getting crystals in the first place. We have also thought of trying 
> microseeding to have more control on nucleation issues. Our protein 
> production is quite limiting and forces us to be very selective with 
> our experimentation.
>
> Nonetheless, while we are waiting for fresh material to explore some 
> of these ideas we would like to make the most out of the crystals we 
> have grown thus far. We would therefore very much appreciate any 
> input/ideas on manipulating these crystals for data collection.
>
> Best wishes
>
> Savvas
>
> ----
> Savvas Savvides
> L-ProBE, Unit for Structural Biology
> Ghent University
> K.L. Ledeganckstraat 35
> 9000 Ghent, BELGIUM
> office: +32-(0)9-264.51.24 ; mobile: +32-(0)472-92.85.19
> Email: [log in to unmask]
> http://www.lprobe.ugent.be/xray.html
>
> *From:* CCP4 bulletin board [mailto:[log in to unmask]] *On Behalf 
> Of *Katarina Moravcevic
> *Sent:* Tuesday, January 27, 2009 10:52 PM
> *To:* [log in to unmask]
> *Subject:* [ccp4bb] pseudo translation
>
> Hi all,
>
> here is a question from a beginner. I have a home source data set that 
> indexed and scaled in a P2 space group (a=46.704,b=59.362, c=48.783, 
> alpha=90.0, beta=104.469, gamma=90.0) with predicted 2mol/au. After 
> failing to get a MR solution with Phaser I ran the phenix.xtriage 
> which showed that I have a large (89.18) Patterson peak at 0.5 0 0.5 
> which indicates pseudo translational symmetry. I was wondering if 
> there is anything I could do with this data to get around this 
> problem. Given that I don't have a lot of experience any 
> suggestion/explanation would be fantastic.
>
> Thanks in advance
>
> K
>
>
>
> *
>
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