Dear Jiyuan,

maybe I can add something from the small molecule crystallographer view :-)

Crystallization:
For crystallization of small molecules you normally use solvents and water
or mixtures as mentioned already before. At my lab the most successful way
to crystallise is evaporation. Please use small glass vials (no plastic,
some solvents will solute them too).

You can also use crystallization kits. Here you can use Bernhard Spinglers
kit and or the Hampton kit. The Hampton kit didn't work so well for my
molecules. I also bought Bernhard's kit but had no time to test it so far.
I have to say I'm only using crystallization kits at the moment as last
try. Maybe that changes in the future.

Measurement:
Of course you can use the synchrotron for small molecules at the protein
beamline. I'm using the PXII protein beamline at the SLS (Swiss light
source) for my small molecules if the crystals are too small for my inhouse
system or there is a problem with my inhouse system. To get the resolution
you need for structure solution and a good refinement you have to change
the wavelength to 0.7Å. Collect always at least 360 degrees  in steps of
0.5 degrees or smaller. Use high filters and short exposure times to secure
your crystal against radiation damage. Normally 10 to 20% of the beam and
0.01 to 0.1 sec work fine depending on the crystal size. Do the measurement
at low temperatures as usual for protein crystals. Here are my parameters
for the SLS-PXII beamline equipped with an Eiger detector (wavelength 0.7Å,
biggest aperture, 20% transmission, step 0.1 deg/0.01 sec, 1800 degrees,
100K).

Processing, structure solution and refinement:
I process the eiger data with XDS,
for structure solution I'm using shelxs or shelxd,
for structure refinement shelxl.

But as mentioned before there are a lot of programs doing processing,
structure solution and refinement. I just started to use Olex as well for
solution and refinement. In very earlier times I also used hkl2000 for data
processing but in my opinion XDS is doing a very good job for small
molecule data.

Last but not least I deeply agree with Navdeep to read Mueller et al.'s
excellent book about Crystal Structure Refinement.

Hope this helps a little bit :-)

Best regards,
André






André Alker
Senior Scientist, pCMC Analytics
Roche Pharmaceutical Research and Early Development
Roche Innovation Center Basel
F. Hoffmann-La Roche Ltd
Grenzacherstrasse 124
4058 Basel, Switzerland
Phone: +41-61-6880935
email: andre_m.al...@roche.com

Upcoming absences:
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On Wed, Jun 3, 2020 at 7:40 PM Navdeep Sidhu <sid...@gmail.com> wrote:

> Dear Jiyuan,
>
> There was a similar question on the bulletin board some 6 years ago; my
> response then (links below) complements some of the other great
> suggestions already made in answer to your question:
>
> <https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind1403&L=CCP4BB&P=R355103
> >,
> and
> <https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind1403&L=CCP4BB&P=R358060
> >.
>
> I believe some 90% of small molecule structures are solved using the
> SHELX suite of programs by Prof. Sheldrick, so that should be a great
> start. The programs are very easy to use, with great defaults. (There
> used to be a joke that to solve this or that problem, all you had to do
> is start one of his programs and press enter 5 times.)
>
> As before, I'd highly recommend you read Mueller et al.'s excellent book
> with detailed tutorials. It provides the data and walks you through
> detailed examples in solving and refining small molecule structures:
>
> Peter Müller, Regine Herbst-Irmer, Anthony Spek, Thomas Schneider and
> Michael Sawaya. IUCr/Oxford, 2006
> <http://ukcatalogue.oup.com/product/9780198570769.do>.
>
> I'm sure you'll have much fun doing small molecules in addition to large
> molecules. We all did.
>
> All the best,
> Navdeep
>
>
> ---
> On 01.06.20 23:50, Jiyuan Ke wrote:
> > Hi Everyone,
> >
> > I want to crystallize a small organic molecule. I have very limited
> > experience in small molecule crystallography. I found that the Crystal
> > Screen HT from the Hampton research is good for both small molecule and
> > macromolecule crystallization. Plan to set up a sitting drop screen just
> > like setting up protein crystallization. I don’t know if this is the
> > proper way to do it. Is the MRC sitting drop 2-well plate (HR3-083) used
> > for protein crystallization good for small molecule crystallization? Are
> > there any special plates used for small molecule crystallization? Is
> > room temperature ok or not?
> >
> > For data collection, can I use the beamline for protein crystals to
> > collect data on small molecule crystals? Larger oscillation angle,
> > shorter exposure, reduced beam intensity?
> >
> > For structure determination, is SHELXL the preferred software for
> > solving small molecule structures?
> >
> > If anyone has experience in small molecule crystallography, please
> > help.  Thanks!
> >
> > Best Regards,
> >
> > --
> >
> > *Jiyuan Ke, Ph.D.*
> >
> > *
> > *
> >
> > Research Investigator
> >
> > H3 Biomedicine Inc.
> >
> > 300 Technology Square, Floor 5
> >
> > Cambridge, MA 02139
> >
> > Phone: 617-252-3923
> >
> > Email: jiyuan...@h3biomedicine.com <mailto:jiyuan...@h3biomedicine.com>
> >
> > Website: www.h3biomedicine.com <http://www.h3biomedicine.com/>
> >
> >
> >
> >
> >
> >
> >
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