Generally speaking, don't we agree that "planned" or "rational" is better than "random?" (Having trouble understanding the argument for randomness here...)
Jacob On Fri, Nov 18, 2011 at 9:40 AM, Sanishvili, Ruslan <[email protected]> wrote: > Depending on the crystal shape, “random orientation” is not always random. > Many crystals have tendencies of sitting themselves in one predominant > posture in the mount. Compounding this, many experimenters have tendencies > of rotating the mount into a specific orientation when centering. Then > crystal orientation ends up being not random at all, so understanding it’s > true orientation as my neighbor Frank suggests can be highly beneficial. > > Cheers, > > N. > > > > Ruslan Sanishvili (Nukri), Ph.D. > > GM/CA-CAT > Biosciences Division, ANL > 9700 S. Cass Ave. > Argonne, IL 60439 > > Tel: (630)252-0665 > Fax: (630)252-0667 > [email protected] > > ________________________________ > > From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Frank > von Delft > Sent: Friday, November 18, 2011 2:27 AM > To: [email protected] > Subject: Re: [ccp4bb] crystal orientation during data collection > > > > 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 <[email protected]> > > Date: > > November 17, 2011 4:00:06 PM CST > > To: > > [email protected] > > Subject: [ccp4bb] crystal orientation during data collection > > Reply-To: > > yanwu huo <[email protected]> > > 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:[email protected] > > > > > > > > > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program email: [email protected] *******************************************
