[ccp4bb] Fortran runtime error in Procheck on Mac OS X 10.6.8
Dear colleagues, I have a problem running procheck on Mac OS X 10.6.8. It stops with the following error: .. Stereochemical quality plots and residue-by-residue listing At line 2639 of file /sw64/src/fink.build/ccp4-6.2.0-101/ccp4-6.2.0/src/procheck/pplot.f (unit = 14, file = 'rama.sum') Fortran runtime error: Sequential READ or WRITE not allowed after EOF marker, possibly use REWIND or BACKSPACE I would appreciate any help. Thank you and best wishes, Alex -- Alex Batyuk The Plueckthun Lab www.bioc.uzh.ch/plueckthun
[ccp4bb] map file specification
Hi, I am looking at the specifications of the ccp4 map file format and I am confused with the number of columns and the number of intervals. I assume that the number of columns is the grid size but what is the number of intervals (elements 8-9 in the header)? Regards, Pascal
Re: [ccp4bb] Fortran runtime error in Procheck on Mac OS X 10.6.8
Hello Alex, I know nothing about Procheck but the following may be of interest to you. There is a similar error message produced during ARP/wARP model building as described in the message below: https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=CCP4BB;30c74e5a.1109 This error was found to be caused by the behaviour of gfortran 4.6.x which is currently used by Fink. If your problem is related to the ARP/wARP issue then you should be able work around it by installing CCP4 from the DMG file provided on the CCP4 site. This DMG file contains executables compiled by the Intel Fortran compiler. Saul Hazledine On Sep 15, 2011, at 8:48 AM, Alexander Batyuk wrote: Dear colleagues, I have a problem running procheck on Mac OS X 10.6.8. It stops with the following error: .. Stereochemical quality plots and residue-by-residue listing At line 2639 of file /sw64/src/fink.build/ccp4-6.2.0-101/ccp4-6.2.0/src/procheck/pplot.f (unit = 14, file = 'rama.sum') Fortran runtime error: Sequential READ or WRITE not allowed after EOF marker, possibly use REWIND or BACKSPACE I would appreciate any help. Thank you and best wishes, Alex -- Alex Batyuk The Plueckthun Lab www.bioc.uzh.ch/plueckthun
Re: [ccp4bb] map file specification
typo: MAPC, MAPR and MAPS are elements 17-19 of the header, but you can see that anyway from the specification. Cheers -- David On 15 September 2011 09:51, David Waterman dgwater...@gmail.com wrote: Hi Pascal, The map data is a three dimensional array with dimensions [NC, NR, NS]. On its own, this gives you no information about the grid pitch in the three (crystallographic, not Cartesian) directions, which is determined in fractional coordinates by the number of intervals. That is, along the X direction the sampling interval has size 1/NX. Of course, you need the X, Y and Z lengths (elements 11-13) to convert the fractional coordinate sizes to real space units. There is a further conversion to take into account too: the correspondence between X, Y, Z and C, R, S is not fixed by the format, but is file dependent and described by MAPC, MAPR and MAPS (elements 11-13). Hope this helps, -- David On 15 September 2011 08:30, Pascal pascal...@parois.net wrote: Hi, I am looking at the specifications of the ccp4 map file format and I am confused with the number of columns and the number of intervals. I assume that the number of columns is the grid size but what is the number of intervals (elements 8-9 in the header)? Regards, Pascal
Re: [ccp4bb] map file specification
Hi Pascal, The map data is a three dimensional array with dimensions [NC, NR, NS]. On its own, this gives you no information about the grid pitch in the three (crystallographic, not Cartesian) directions, which is determined in fractional coordinates by the number of intervals. That is, along the X direction the sampling interval has size 1/NX. Of course, you need the X, Y and Z lengths (elements 11-13) to convert the fractional coordinate sizes to real space units. There is a further conversion to take into account too: the correspondence between X, Y, Z and C, R, S is not fixed by the format, but is file dependent and described by MAPC, MAPR and MAPS (elements 11-13). Hope this helps, -- David On 15 September 2011 08:30, Pascal pascal...@parois.net wrote: Hi, I am looking at the specifications of the ccp4 map file format and I am confused with the number of columns and the number of intervals. I assume that the number of columns is the grid size but what is the number of intervals (elements 8-9 in the header)? Regards, Pascal
[ccp4bb] The 2012 CCP4 Study Weekend on Data Processing
CCP4 Study Weekend - 4-6 January 2012 We cordially invite you to participate in this year's Study Weekend at the Warwick Conferences, University of Warwick. Once again, we have put together an exciting scientific programme for Thursday and Friday, either side of the traditional conference dinner. Please also check out the satellite meetings which may be of interest - we have scheduled in a session of What's New in CCP4. The Study Weekend is a chance to catch up with old friends, but is also a chance to meet the CCP4 staff who will be there in force to demonstrate the latest software and to answer questions. This year, the topic for the Study Weekend is Data Collection and Processing. In keeping with previous CCP4 meetings, the lectures will focus on the presentation and discussion of advanced methods and techniques developed and used by the leaders in the field. We are holding the main CCP4 Study Weekend talks in the Arts Centre on the Warwick Campus which is a larger theatre than last year's Ramphal and so should prove more comfortable for delegates. Scientific Organisers Johan Turkenburg - University of York (UK) Katherine McAuley - Diamond Light Source (UK) Further information at: http://www.cse.scitech.ac.uk/events/CCP4_2012/ the program at: http://www.cse.scitech.ac.uk/events/CCP4_2012/programme.html and registration at: http://www.cse.scitech.ac.uk/events/CCP4_2012/registration.html Charles Ballard CCP4
[ccp4bb] UV imaging of crystals
Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Thanks so much, Christine
Re: [ccp4bb] UV imaging of crystals
I'm not going to respond to the larger group, but I know one can buy LEDs that emit strongly at 280 nm, which would give tryptophan fluorescence. They're about $200, and one could build or buy a control circuit for not much more. I think this is about what the commercial tools do. You'd want front illumination. You can get the LED with a convex lens on the front, giving a focus about 1 away. At that point the light is dangerous -- don't shine it into your eye from that distance. You'd want to ask your local safety guys to check it out. We would use it at the synchrotron with a flash circuit that would be synchronized with a video camera -- I think roughly 20ms would do it. Let me know if it works. Bob = Robert M. Sweet E-Dress: sw...@bnl.gov Group Leader, PXRR: Macromolecular ^ (that's L Crystallography Research Resource at NSLSnot 1) http://px.nsls.bnl.gov/ Biology Dept Brookhaven Nat'l Lab. Phones: Upton, NY 11973631 344 3401 (Office) U.S.A. 631 344 2741 (Facsimile) = On Thu, 15 Sep 2011, Harman, Christine wrote: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Thanks so much, Christine
Re: [ccp4bb] UV imaging of crystals
Quoting Harman, Christine christine.har...@fda.hhs.gov: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ This message was sent using IMP, the Internet Messaging Program.
Re: [ccp4bb] UV imaging of crystals
On Thu, 2011-09-15 at 20:50 +0100, Andrew Purkiss-Trew wrote: Molecular Dimension do such an adaptor which fits to existing microscopes. Do you by any chance know the price? I can seemingly order it through the website for the hefty price of $0.00, which is too good to be true. -- Hurry up before we all come back to our senses! Julian, King of Lemurs
Re: [ccp4bb] UV imaging of crystals
A while ago I was trying to be cheap, so we played around with it quite a bit in the lab. After rediscovering some of the basics of signal-to-noise and microscope transmission efficiency and that sort of rot, I realised that the commercial systems may not be all that ridiculously overpriced after all. Not if one wants to be able to say something useful about really really small crystals -- the only ones that really matter in the grand scheme of things (big ones are quick to test; little ones must first be optimized = money+time). But maybe I was just being incompetent. Happens. phx. On 15/09/2011 20:50, Andrew Purkiss-Trew wrote: Quoting Harman, Christinechristine.har...@fda.hhs.gov: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ This message was sent using IMP, the Internet Messaging Program.
[ccp4bb] Why Does Cross-linking Mean Anything?
Dear Crystallographers and Biochemists, cross-linking, say with gluteraldehyde, is an oft-used method of demonstrating a protein's oligomeric state in solution. I have a difficulty with this, however: theoretically (and in practice!), one can tune the amount of cross-linker to get what ever result is desired, such that any protein with some exposed lysines can be cross-linked in any oligomeric state. How, then, does one evaluate the power of this evidence? Maybe one should do a gradient of gluteraldehyde concentrations, then plot the deviation of the observed cross-linked oligomerization from a theoretical null hypothesis? Seems like this could be done, but I have never seen this in the literature... Best, Jacob Keller -- *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu ***
Re: [ccp4bb] Why Does Cross-linking Mean Anything?
On Thu, 2011-09-15 at 15:10 -0500, Jacob Keller wrote: Maybe one should do a gradient of gluteraldehyde concentrations, then plot the deviation of the observed cross-linked oligomerization from a theoretical null hypothesis? Right - just do it side-by-side with a protein known to be monomeric of roughly the same size/lysine content... And what is the critical concentration of gutaraldehyde at which the false positives appear in your experience? -- I'd jump in myself, if I weren't so good at whistling. Julian, King of Lemurs
Re: [ccp4bb] UV imaging of crystals
I once tested such a commercial system in Seattle about 4 years ago. It did not impress me. In particular the discrimination between salt and protein did not work for about 10 different proteins from which we already had collected data. sure those were small between 10 and 100 micrometer. Excuse was to few tryptophans So in theory it is nice but a cheaper variant might be to add Gfp to your protein and screen for something green. Jürgen .. Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Sep 15, 2011, at 16:03, Frank von Delft frank.vonde...@sgc.ox.ac.uk wrote: A while ago I was trying to be cheap, so we played around with it quite a bit in the lab. After rediscovering some of the basics of signal-to-noise and microscope transmission efficiency and that sort of rot, I realised that the commercial systems may not be all that ridiculously overpriced after all. Not if one wants to be able to say something useful about really really small crystals -- the only ones that really matter in the grand scheme of things (big ones are quick to test; little ones must first be optimized = money+time). But maybe I was just being incompetent. Happens. phx. On 15/09/2011 20:50, Andrew Purkiss-Trew wrote: Quoting Harman, Christinechristine.har...@fda.hhs.gov: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ This message was sent using IMP, the Internet Messaging Program.
Re: [ccp4bb] UV imaging of crystals
Quoting Ed Pozharski epozh...@umaryland.edu: On Thu, 2011-09-15 at 20:50 +0100, Andrew Purkiss-Trew wrote: Molecular Dimension do such an adaptor which fits to existing microscopes. Do you by any chance know the price? I can seemingly order it through the website for the hefty price of $0.00, which is too good to be true. Sorry, I don't know, I think that a new PI at our institute has ordered one from his new equipment budget. But I don't have a price to hand, I can ask though. -- Andrew Purkiss-Trew X-ray Laboratory Manager London Research Institute Cancer Research UK This message was sent using IMP, the Internet Messaging Program.
Re: [ccp4bb] Why Does Cross-linking Mean Anything?
Maybe one should do a gradient of gluteraldehyde concentrations, then plot the deviation of the observed cross-linked oligomerization from a theoretical null hypothesis? Right - just do it side-by-side with a protein known to be monomeric of roughly the same size/lysine content... And what is the critical concentration of gutaraldehyde at which the false positives appear in your experience? The critical concentration depends on protein concentration, time of reaction, brand of gluteraldehyde, day of week, color of my shirt No, I don't know--I have seen cross-linking gradients in Nature and such in which several oligomeric states can be seen up to the one the author asserts is the physiological one. This is a nice experiment for proving one's point on paper, but maybe not for establishing the truth? Maybe a control with some SDS would be appropriate (although this would probably perturb the lysines). Or maybe the experiment should be done in a lysate, and then western-blotted? Jacob -- *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu ***
[ccp4bb] Ph.D. fellowships in Structural Biology at the European Institute of Oncology, Milan
PhD Fellowships to study molecular mechanisms of Asymmetric Cell Divisions at IEO, Milano Applications are invited for two Ph.D. positions to study the structure and function of macromolecular complexes involved in asymmetric cell divisions. To understand mechanisms underlying asymmetric divisions we follow a multidisciplinary approach combining biochemistry, structural biology and cell biology (http://www.ifom-ieo-campus.it/research/mapelli.php). Our studies are expected to have a major impact on the understanding of stem cell biology, with possible applications at the forefront of anticancer therapy and regenerative medicine. We seek motivated and enthusiastic students, who have recently obtained a University degree in Life Science disciplines (or a qualification equivalent to a Master degree). Some experience in biochemistry or structural biology would be advantageous, though not required. Willingness to study protein functions with biochemical and biophysical methods, as well as interest in learning protein crystallography are essential. The Ph.D. positions are within the SEMM Ph.D. in Molecular Medicine program (http://www.semm.it/). The closing date for applications to SEMM is September 25, 2011. The Structural Biology Department of the IFOM-IEO Campus is equipped with the state-of-the-art apparatus for protein purification, characterization and crystallization, and has good access to the synchrotron beamlines. Successful candidates will benefit from a stimulating and collaborative environment within the Campus (http://www.ifom-ieo-campus.it/). I am looking forward to meeting you at the selections. With kind regards, Marina - Marina Mapelli, PhD Department of Experimental Oncology European Institute of Oncology Via Adamello 16, I-20139 Milan, Italy tel: ++39-02-94375018 email: marina.mape...@ifom-ieo-campus.it web: http://www.ifom-ieo-campus.it/research/mapelli.php
Re: [ccp4bb] Why Does Cross-linking Mean Anything?
Dear Jacob, agree, it's a mess. From what I read, the glutataldehyde concentration should be low (0.01%) and the x-linked complex that you get should not occur in high salt conditions (reasoning that 1.2M KCl would break the average complex apart). Have seen papers where more selective zero length crosslinkers have been used - the Pierce catalog used to have lots of them - it seems it boils down to the same problem, eventually you will find one that works but you will need independent evidence to convince yourself. I typically make really nice MW size ladders with my monomeric negative control proteins, though. Best, Herwig * * * * * * * * * * * * * * Herwig Schüler, PhD PI, Structural Biochemistry Structural Genomics Consortium, MBB Karolinska Institutet Scheeles väg 2 S-17177 Stockholm
Re: [ccp4bb] UV imaging of crystals
I'm replying here to myself :-) So in an off-board discussion it turns out that the microscope in question was a special emitted light and not a UV microscope. So real UV microscopes might be better for the purpose of detecting real crystals. Sorry for the confusion - had too much sun today :-) Jürgen On Sep 15, 2011, at 4:19 PM, Jürgen Bosch wrote: I once tested such a commercial system in Seattle about 4 years ago. It did not impress me. In particular the discrimination between salt and protein did not work for about 10 different proteins from which we already had collected data. sure those were small between 10 and 100 micrometer. Excuse was to few tryptophans So in theory it is nice but a cheaper variant might be to add Gfp to your protein and screen for something green. Jürgen .. Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Sep 15, 2011, at 16:03, Frank von Delft frank.vonde...@sgc.ox.ac.uk wrote: A while ago I was trying to be cheap, so we played around with it quite a bit in the lab. After rediscovering some of the basics of signal-to-noise and microscope transmission efficiency and that sort of rot, I realised that the commercial systems may not be all that ridiculously overpriced after all. Not if one wants to be able to say something useful about really really small crystals -- the only ones that really matter in the grand scheme of things (big ones are quick to test; little ones must first be optimized = money+time). But maybe I was just being incompetent. Happens. phx. On 15/09/2011 20:50, Andrew Purkiss-Trew wrote: Quoting Harman, Christinechristine.har...@fda.hhs.gov: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ This message was sent using IMP, the Internet Messaging Program. .. Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://web.mac.com/bosch_lab/
Re: [ccp4bb] UV imaging of crystals
A real UV microscope requires quartz optics, right? Probably conventional microscopes use glass. And you can't see 280 nm (and its not good for your eyes) so you need some kind of phosphor screen to view the image? Bosch, Juergen wrote: I'm replying here to myself :-) So in an off-board discussion it turns out that the microscope in question was a special emitted light and not a UV microscope. So real UV microscopes might be better for the purpose of detecting real crystals. Sorry for the confusion - had too much sun today :-) Jürgen On Sep 15, 2011, at 4:19 PM, Jürgen Bosch wrote: I once tested such a commercial system in Seattle about 4 years ago. It did not impress me. In particular the discrimination between salt and protein did not work for about 10 different proteins from which we already had collected data. sure those were small between 10 and 100 micrometer. Excuse was to few tryptophans So in theory it is nice but a cheaper variant might be to add Gfp to your protein and screen for something green. Jürgen .. Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Sep 15, 2011, at 16:03, Frank von Delft frank.vonde...@sgc.ox.ac.uk wrote: A while ago I was trying to be cheap, so we played around with it quite a bit in the lab. After rediscovering some of the basics of signal-to-noise and microscope transmission efficiency and that sort of rot, I realised that the commercial systems may not be all that ridiculously overpriced after all. Not if one wants to be able to say something useful about really really small crystals -- the only ones that really matter in the grand scheme of things (big ones are quick to test; little ones must first be optimized = money+time). But maybe I was just being incompetent. Happens. phx. On 15/09/2011 20:50, Andrew Purkiss-Trew wrote: Quoting Harman, Christinechristine.har...@fda.hhs.gov: Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ This message was sent using IMP, the Internet Messaging Program. .. Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://web.mac.com/bosch_lab/
[ccp4bb] crystallization of complex and ...
Dear all, I have two questions: First, I was trying to crystallize a complex of two proteins. Both proteins has been crystallized before. The two proteins bind to each other based on Biacore study, but they didn't form a single peak on gel filtration. When I mixed them at 1:1 ratio, the crystals I got contain only one of the two proteins. I was suggested to increase the ratio, for example 1.5:1, to increase the probability of co-crystallization which I will try. But I do want to hear if there are other possible ways to try. What would you try if you were in my situation? Second is about reusing of Ni-NTA resin. According to Qiagen's instruction, after using fresh Ni-NTA resin, one only needs to wash the used Ni resin first with 0.5M NaOH, then with your own buffer. After that the resin is ready to be reused until it needs being recharged. But my question is: Once immidazole competes with His-tagged protein and binds to Ni-resin, how can immidazole be rinsed off with the same buffer(usually pH is above 7) one uses to purify the protein? Thank you for any suggestion or comment. Min
Re: [ccp4bb] UV imaging of crystals
Typically, what you image is Trp fluorescence by exciting at around 280 nm and observing at around 350 nm. Standard silicon based detectors do fine at the detection wavelength, although, as you can imagine, increased sensitivity in the UV means increase in the price of the detector. If your excitation and emission light paths do not overlap, you also can get by with standard glass (crown, flint, etc.) optics since they do allow some of the 350-nm light to get through. Therefore, yes, it is possible to build an inexpensive UV imager based on inexpensive excitation light source (Douglas Instruments offers a pen light), and standard lab microscope. Of course, for increased sensitivity and contrast you need a very good light source, optics made of quartz and calcium fluoride that let almost all the UV light through, highly discriminating filters and a sensitive detector. V. Nagarajan JANSi http://janscientific.com On Thu, Sep 15, 2011 at 7:07 PM, Edward A. Berry ber...@upstate.edu wrote: A real UV microscope requires quartz optics, right? Probably conventional microscopes use glass. And you can't see 280 nm (and its not good for your eyes) so you need some kind of phosphor screen to view the image? Bosch, Juergen wrote: I'm replying here to myself :-) So in an off-board discussion it turns out that the microscope in question was a special emitted light and not a UV microscope. So real UV microscopes might be better for the purpose of detecting real crystals. Sorry for the confusion - had too much sun today :-) Jürgen On Sep 15, 2011, at 4:19 PM, Jürgen Bosch wrote: I once tested such a commercial system in Seattle about 4 years ago. It did not impress me. In particular the discrimination between salt and protein did not work for about 10 different proteins from which we already had collected data. sure those were small between 10 and 100 micrometer. Excuse was to few tryptophans So in theory it is nice but a cheaper variant might be to add Gfp to your protein and screen for something green. Jürgen .. Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Sep 15, 2011, at 16:03, Frank von Delft frank.vonde...@sgc.ox.ac.uk wrote: A while ago I was trying to be cheap, so we played around with it quite a bit in the lab. After rediscovering some of the basics of signal-to-noise and microscope transmission efficiency and that sort of rot, I realised that the commercial systems may not be all that ridiculously overpriced after all. Not if one wants to be able to say something useful about really really small crystals -- the only ones that really matter in the grand scheme of things (big ones are quick to test; little ones must first be optimized = money+time). But maybe I was just being incompetent. Happens. phx. On 15/09/2011 20:50, Andrew Purkiss-Trew wrote: Quoting Harman, ChristineChristine.Harman@**FDA.HHS.GOVchristine.har...@fda.hhs.gov : Hi All, I was curious if any of you have tried or even know if it is possible to adapt a stereoscope (in my case an Olympus SZX10 model) so as to view protein crystals with UV illumination. Basically, I want a cheap manual version of what a Rock UV Imager does. I know this is probably a crazy dream. However, I would greatly appreciate any comments, advice or experience any of you may have. Molecular Dimension do such an adaptor which fits to existing microscopes. See http://www.**moleculardimensions.com/**shopdisplayproducts.asp?id=** 121cat=X%2DtaLight%3Csup%3E%**99%3C%2Fsup%3E+100+%2D+UV+for+** Microscope+http://www.moleculardimensions.com/shopdisplayproducts.asp?id=121cat=X%2DtaLight%3Csup%3E%99%3C%2Fsup%3E+100+%2D+UV+for+Microscope+ --**--** This message was sent using IMP, the Internet Messaging Program. .. Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://web.mac.com/bosch_lab/
