Dear Jacob, dear TO, (I have wondered what can be 'micro' about diffraction - would you know?)
it would be very exciting to get the structure by electron diffraction - as much as I know it would be the first new structure solved from a 3D crystal with electron radiation in the PDB. You would have to contact one of the 3-4 labs that to electron diffraction of protein samples (Abrahams, Gonen, Hovmoeller / Zou (possibly), and Yonekura/Toyoshima in alphabetic order). The first and the last group are equipped with sensitive hybrid pixel detectors that might help. A good test to get an idea about the resolution you might get from electron diffraction is to scratch up as many of your crystals and analyse the powder pattern with a strong X-ray source (synchrotron, or very good home source). Note that when you can see the crystals with a light microscope, they are most likely too big for electron diffraction - you might end up seeing a black screen with no electron penetrating your samples. Best regards, Tim On Wednesday, March 1, 2017 1:59:44 PM CET Keller, Jacob wrote: > Although trying to refine the crystals is perhaps the most straightforward > thing, you might consider trying micro electron diffraction (micro-ED) with > the existing samples—the technique is working increasingly better, and > would work well with your tiny crystals. Look at Tamir Gonen’s recent > papers for more info. > All the best, > > Jacob Keller > > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of ??? > Sent: Wednesday, March 01, 2017 3:53 AM > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] How to refine this needle crystal of membrane complex? > > Dear all, > I am trying to obtain crystals of membrane complex. Now, I have obtained the > complex with appropriate stoichiometry after a series of purification in > DDM, then I get extremely thin needles (as shown in figure) in some > conditions such as 28% MPD, 0.1 M NaAc pH 4.5 or 45% MPD,0.1 M Bis-Tris pH > 6.5, 0.2 M CaCl2. However, there are not any improvements through changing > the concentration of precipitants/salts or adding the additives/detergents > to the protein. > I would be very happy if anybody could give me some advice about this > crystal refinement. > With best regards. > > > [cid:image001.png@01D2926A.28CB0C70] -- -- Paul Scherrer Institut Tim Gruene - persoenlich - OFLC/104 CH-5232 Villigen PSI phone: +41 (0)56 310 5297 GPG Key ID = A46BEE1A
signature.asc
Description: This is a digitally signed message part.
