Their web page indicates they’re running a 315, so there are limits on useful low dose data collection. If you can get to a beamline with a pixel array detector and mount your samples carefully you’ll probably get more from low dose methods.
The key thing with this is minimising background from loop, drop etc so the photons you measure are as far as possible from the sample under study. You’ll probably benefit from combining data from multiple samples if they are isomorphous. Obviously your ultimate resolution will be limited by the number of photons your sample can scatter before suffering measurable damage... but combining samples can help you here Best wishes Graeme On 29 Aug 2019, at 19:07, Kimberly Stanek <ksta...@uci.edu<mailto:ksta...@uci.edu>> wrote: ALS 822. I tried as low as 0.2 sec exposure but it didn't seem to help much. Kimberly Stanek Postdoctoral Researcher, Goulding Lab Co-chair, UCI Postdoctoral Association University of California, Irvine Natural Science I, Room 2302 (949) 824-0014 ________________________________ From: James Holton <jmhol...@lbl.gov<mailto:jmhol...@lbl.gov>> Sent: Thursday, August 29, 2019 10:50 AM To: Kimberly Stanek <ksta...@uci.edu<mailto:ksta...@uci.edu>>; CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK> <CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>> Subject: Re: [ccp4bb] Semet derivative dying almost immediately in beam What exposure time are you using? And which beamline? -James Holton MAD Scientist On 8/29/2019 10:26 AM, Kimberly Stanek wrote: Hi folks, We have a protein that we have been trying to solve the structure of for a while now but so far haven't been able to get any diffraction better than ~4.5A. I was able to collect a full 360 degrees of data and index, but MR is failing so we have turned to de novo phasing. Recently we prepared crystals of the Semet derivative under the same condition. While these crystals diffracted to about the same resolution, I found they were dying after just one or two snaps, even with increased beam attenuation and decreased exposure time. I am wondering if anyone has experienced anything like this before and had any suggestions on what to do about it. Thank you, Kimberly Stanek Postdoctoral Researcher, Goulding Lab Co-chair, UCI Postdoctoral Association University of California, Irvine Natural Science I, Room 2302 (949) 824-0014 ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
