Hi Stefan, It looks like a powder diffraction-type image.
http://en.wikipedia.org/wiki/Powder_diffraction You can imagine that your spherulites are made up of many small crystals in random orientations, a bit like a powder - this means that rather than getting discrete diffraction spots as you would hope to see for a single crystal, you see diffraction rings around the beam centre. HTH, Dave ============================ David C. Briggs PhD Father, Structural Biologist and Sceptic ============================ University of Manchester E-mail: david.c.bri...@manchester.ac.uk ============================ http://manchester.academia.edu/DavidBriggs (v.sensible) http://xtaldave.wordpress.com/ (sensible) http://xtaldave.posterous.com/ (less sensible) Twitter: @xtaldave Skype: DocDCB ============================ On 6 April 2011 09:32, Stefan Münnich <smunn...@vub.ac.be> wrote: > Hey guys, > > When I collect data from these spherulites/crystals (grown in 0.1 M sodium > acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM > NaCl, 50 mM HEPES pH 7.5): > http://img695.imageshack.us/i/cryst.png/ > I get this diffraction pattern: (it's not cryo protected, so there's some > ice-rings also) > http://img683.imageshack.us/i/diffv.jpg/ > > It can't be only ice-rings because those are usually starting at something > like 3.8 A, whereas I already got one ring directly around the beam center > and also one at about 20 A. > Has anybody seen anything like that and tell me what it is? > > Stefan
