Hi SnowDeer- What's your precipitant? Have you tried lowering that as much as possible? This will likely delay nucleation and crystal growth but the crystals will also likely be larger (and perhaps more well ordered). Of course, you may reach a lower limit where you prohibit nucleation. You'll have to determine this empirically. How about smaller reservoir volumes while keeping the drop volume the same? Have you tried setting up and storing trays at lower temperatures, 10 C or less? Sitting drop vs. hanging drop? Different oils in your vapor diffusion experiments, like Al's oil? Also, I had success with growing large crystals by setting up microbatch drops under oil. If you'd like details, I can provide them off-board.
Cheers- Brad On Thu, Sep 8, 2011 at 3:52 AM, SnowDeer <huanxu...@gmail.com> wrote: > To Boaz: I seperated the large crystals and checked its diffraction > already. While the diffraction is quite poor, only several dots could be > seen. T_T > I washed the seeds twice with my buffer and seed the drop immediately after > setting it. Thanks for your advices and I will try the additives. > > To Charles, Enrico, Bernie & Tiantian: Thanks for your kindly advices, I > set different conditions for the buffers with glycerol and different > protein/reservoir volume ratios already following your instructions. :) > > To David: Hmm...my crystals are smaller than the smallest loop T_T. It's > quite hard for me to pick them up (due to my clumsy fingers...lol). Thanks > for your advices and the review. > > I have another question: I usually stored my protein samples aliquots at > -80 degree and thaw the small aliquots when I need to use. While my senior > said it will harm the protein so she suggested to keep them at 4 degree. So > it is possible that I got the small crystals coz the freezing and thawing > alter the proteins? > > Thanks very much. > SnowDeer > > On Tue, Sep 6, 2011 at 9:39 PM, David Waterman <dgwater...@gmail.com>wrote: > >> Dear SnowDeer, >> >> Just how small is too small? If you have access to a microfocus beamline >> you might find you can collect decent diffraction data from crystals with >> dimensions in the single digit microns. Fishing tiny crystals is difficult, >> but something like the MicroMesh "tennis racquet" mounts can help. Having >> multiple crystals on the same pin is in fact a rather helpful way of >> screening lots of samples. Please don't discount your crystals _only_ >> because they are small! >> >> Shameless plug: there is a review on microcrystallography here that you >> might find interesting. >> http://www.tandfonline.com/doi/abs/10.1080/0889311X.2010.527964 >> >> Best wishes >> >> -- David >> >> >> >> On 5 September 2011 09:06, SnowDeer <huanxu...@gmail.com> wrote: >> >>> Dear All: >>> >>> Recently I am working on a protein which can already grow nice >>> pyramid-like crystals after the condition was optimized, while the crystals >>> are too small to be picked up. The crystals grew quite fast and densely, so >>> I tried to put 100ul paraffin oil inside the 600ul reservoir solution or put >>> the plate under 16 degree to slow down the evaporation, while the crystals >>> were still the same. I also tried macro or micro seeding with or without the >>> paraffin oil. Macroseeding would give a larger crystal (not very nice) with >>> many small crystals in the drop even I washed the seeds carefully. For >>> microseeding, the same small crystals grew. >>> >>> I don't have many experiences in crystallography, so I have no idea how >>> to make it grow bigger... >>> >>> Any suggestion is most welcome. >>> >>> Thanks. >>> SnowDeer >>> >> >> >
