Hi Sam, Yes. I've had 2 different crystal forms from the same drop. C2 vs C2221. Completely different packing, despite that fact that 2 of the cell edges were within an angstrom or two of each other. In the above case, I soaked ligand into the crystals, one form had ligand bound, one didn't, despite the fact that the binding site was available in both cases.
I think you just need to proceed on a crystal-by-crystal basis and make zero assumptions during data collection. HTH, Dave On Fri, 28 Oct 2016 at 14:13 Sam Tang <[email protected]> wrote: > Dear all > > Sorry for going a bit off-topic in this thread. > May I seek your advice as on whether you have experienced that crystals > being obtained from the same droplet, looking alike under microscope (rod > shape) and in fact growing possibly from a same nuclei, give two space > groups after indexing? > > I recently obtain crystals for a protein (co-crystallized with a nucleic > acid ligand) and collected two datasets from synchrotron. Although these > two crystals are from the same drop, the SG and unit cell dimensions are > very different: > > Xtal1: C121 (156 60 105 90 111 90) (L-test, Pointless shows that there is > no twinning), ~2.5 Angstrom > Xtal2: P1 (53 60 79 106 105 98), ~3 Angstorm > > Would it be possible that the ligand changes the SG of the crystal so that > only one of the forms contains the ligand? > > Any advice is appreciated and thanks a lot in advance for your input. > > Regards > > Sam Tang > Biochemistry Programme, School of Life Sciences, CUHK > > -- [image: --] David Briggs PhD [image: https://]about.me/david_briggs <https://about.me/david_briggs?promo=email_sig&utm_source=email_sig&utm_medium=email_sig&utm_campaign=external_links>
