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The most carefully monitored connection between crystal growth and
vibration I am aware of was made by Eddie Snell's group with their
experiments on the Space Shuttle:
http://scripts.iucr.org/cgi-bin/paper?gr0718
E. H. Snell, T. J. Boggon, J. R. Helliwell, M. E. Moskowitz and A.
Nadarajah, /Acta Cryst./ (1997). D*53*, 747-755
They saw a very clear conneciton between vibrations and crystal growth
rates and indeed crystal quality. Things like "astronaut exercising"
coincided with increased crystal growth rate a short time later. So, it
would appear that even in the most controlled environments vibration
control can be a challenge, but at least on the Shuttle, where
everything gets logged, you can (could) look for relationships.
Hope this is useful.
-James Holton
MAD Scientist
[EMAIL PROTECTED] wrote:
Dear crystallographers,
While this is not a directly CCP4-related project, no crystal (or bad
quality ones) means not much use of CCP4 ... hence the following
inquiry. I am involved in the design of a new crystallisation lab with
temperature-controlled rooms, which we have found to be typically
quite prone to internal vibrations. A little vibration is probably not
an issue in most of the cases, but how to define what is acceptable
and what is not?
Most of the time people define good crystallisation environment as
vibration-free, but I suspect that 0 vibration is not a value that can
be typically achieved in labs (can it be achieved at all?), and while
there are means of measuring vibration levels, I could not find any
numeric references...
...which leads me a long list of naive questions:
- does anyone have performed any vibration level measurement in their
labs and defined a threshold for acceptable conditions?
- are scientists performing their crystallisation experiments in
temperature-controlled rooms satisfied with the vibration levels?
- do some of you recommend some devices/brands to reduce vibrations
applied to the crystallisation trays? (I heard about vibration-free
shelves or insulation pads, is this any good?)
- any advice about how to handle vibration issues welcome!
Thank you very much to all of you in advance,
Ingrid Mechin
