 |
 |
>On Feb 28, 2007, at 14:37, shivesh kumar wrote: > >Dear all, >I have a data set at 2.2A, of the selenomethionene labelled >protein.How should I process the data. Some hopefully useful remarks (fairly random and not complete and exhaustive): 1. make sure to mask out the backstop and beamstop holder correctly. Although various integration software claims to do this fairly automatic it is always better to do a good job on this. 2. check the rejected reflections (at the scaling/merging step): is there some system in those rejections? The two files produced by SCALA (ROGUES and a xmgr file that plots the detector position of rejected reflections) are very helpful. It can show ice-rings, bad beamstop-masking (see point 1) etc. 3. heavy atom detection/phasing software will also write out some helpful information about outliers: if there are some suspicious messages (e.g. warnings in autoSHARP) they usually point back to problems in data processing (see point 1). 4. if you collected several datasets/wavelengths: you can give those to SCALA for some 'local scaling'. This will also show you those really helpful CC(Dano) plots. But be careful with absorption correction: all datasets/sweeps need to be indexed identically. 5. always remember what your first reaction was when looking at the images: 'great' images should give you good statistics further down the pipeline. But if 'awfull' images give you good statistics I would be suspicious ... 6. unless you really know what's going on: stick with program defaults. Usually the developers have a very good idea why the program is doing things in a specific way. Cheers Clemens -- *************************************************************** * Clemens Vonrhein, Ph.D. vonrhein AT GlobalPhasing DOT com * * Global Phasing Ltd. * Sheraton House, Castle Park * Cambridge CB3 0AX, UK *-------------------------------------------------------------- * BUSTER Development Group (http://www.globalphasing.com) ***************************************************************