I don't think one can generalise that much. In the Stuart case of BTV, only 1-3 useful images per crystal could be obtained if I remember correctly - so there the random strategy orientation makes sense. I.e. if you collect one image and then wait until the orientation and strategy is calculated, the crystal is probably already dead. For projects where more images can be collected from a single crystal, I would think it makes more sense to use the strategy options described (like was done for F1-ATPase). Another thing to keep in mind is how to achieve this random orientation, one can not always count on the crystal orienting randomly in a loop, i.e. many crystals have preferred orientations when mounted...and one tends to mount the loop on the goniometer the same way each time. So one would have to use "random" starting phis.
Mark J van Raaij Laboratorio M-4 Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC c/Darwin 3 E-28049 Madrid, Spain tel. (+34) 91 585 4616 http://www.cnb.csic.es/content/research/macromolecular/mvraaij On 18 Nov 2011, at 09:26, Frank von Delft wrote: > I believe you achieve completeness more quickly (fewer crystals) if you just > take random orientations. At least, that's what I learnt from Dave Stuart. > phx > > > > On 18/11/2011 04:20, Frank Murphy wrote: >> Yanwu, >> >> I surmise from your question that you are inquiring how to go about >> collecting from many crystals optimally. Merging data ex post facto is a >> totally different kettle of fish. >> >> In my opinion, the most robust way to go about this is to use a kappa >> goniometer as Jim suggested (I am most familiar with the MK3). Since you >> intend to collect from many crystals, align the first and all subsequent >> crystals to the same easily attainable (or seemingly so) orientation, and >> then collect the sweep suggested by your data collection strategy program of >> choice. >> >> To achieve this at NE-CAT, we have a GUI-based system that used STAC for >> orientation determination and BEST for strategy generation. As Jim >> suggested, more options than STAC exist. >> >> If anyone is unable to get to a kappa goniometer, they can employ Mosflm or >> XDS (Xplan) to generate strategies for data collection from a crystal taking >> into account previously collected data. This is not nearly as robust a >> solution, but is a workable substitute (and also automated at NE-CAT). >> >> I know there are other ways to achieve similar results, but I have suggested >> the methods I am most familiar with... >> >> >> Yours, >> Frank Murphy >> >> >> Begin forwarded message: >> >>> From: yanwu huo <applehu...@gmail.com> >>> Date: November 17, 2011 4:00:06 PM CST >>> To: CCP4BB@JISCMAIL.AC.UK >>> Subject: [ccp4bb] crystal orientation during data collection >>> Reply-To: yanwu huo <applehu...@gmail.com> >>> >>> Hi, >>> I worked on a crystal sensitive to radiation damage, So I need to merge >>> many crystal to obtain complete dataset, Does anyone know such >>> program that can tell crystal orientation after first frame exposure. >>> Thank you in advance. >>> >>> >>> -- >>> Thank you very much and all the best, >>> >>> Yanwu Huo >>> Postdoctoral Associate >>> Department of Molecular Biology and Genetics >>> Cornell University >>> Ithaca, NY, 14853 >>> Email:yh...@cornell.edu >>> >> >> >> >>
