Dear All,
after a few requests, I have now added equations to the online
calculator that uses Raoult's law to calculate the relative humidity
equilibria for precipitant solutions (see http://go.esrf.eu/RH). The new
equations (4 and 5) allow the calculation of salt concentrations that
will be in equilibrium with a certain PEG or other molecule solution -
this will allow slow and controlled dehydration experiments to be
designed in vapour diffusion plates, by slowly increasing the salt
concentration in the reservoir above the equilibrium and thereby
reducing the amount of water in the crystallisation drop by a controlled
amount. Hope it is useful, cheers, Matt.
--
Matthew Bowler
Synchrotron Science Group
European Molecular Biology Laboratory
BP 181, 6 rue Jules Horowitz
38042 Grenoble Cedex 9
France
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Tel: +33 (0) 4.76.20.76.37
Fax: +33 (0) 4.76.88.29.04
http://www.embl.fr/
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