Hi Shijun
I've just seen your message.
A very good solution to this problem was invented by my old colleague, Lesley Haire.
She used a plate with a "moat" (our Vapor Batch plates for microbatch-under-oil). She dispensed the drops without any isopropanol, and covered them with "Al's Oil" (silicone oil mixed with paraffin). Next, she placed first 10% then 20% isopropanol in the moat, and allowed it to diffuse through the oil into the drops. Then she harvested the crystals through the oil layer.
She tried really hard to change the conditions, soak in other precipitants, harvest in a tent containing isopropanol vapor (!) etc. but nothing else worked - the crystals always had high mosaicity. This worked beautifully.
The Al's Oil became saturated with isopropanol and acted as a barrier, preventing evaporation during harvesting.
You can find Lesley's description of the method (including using the same approach for screening) here:
Reference (in Nature!) is below.
You can get Vapor Batch plates from us, Hampton Research or Jena Bioscience (other plates could probably be used too).
This method has worked several times - in fact I've never known it fail :)
I would certainly also run random MMS microseeding as mentioned by Zaigham.
Best wishes
Patrick
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Mortuza GB, Haire LF, Stevens A, Smerdon SJ, Stoye JP, Taylor IA. High-resolution structure of a
retroviral capsid hexameric amino-terminal domain. Nature. 2004 Sep 23;431(7007):481-5.
On 4 August 2016 at 02:20, 张士军
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