Well originally we got these in cacodylate and not much else would diffract. http://www.pdb.org/pdb/explore/materialsAndMethods.do?structureId=2EPH But nowadays I have another conditions, which does not require cacodylate and works well with Hepes.
Jürgen On Nov 9, 2012, at 7:26 AM, Frank von Delft wrote: > Hi all - > > Anybody know > a) how hazardous is cacodylate? > b) does it really matter for crystallization screens? > > It seems by far the most hazardous component of the standard screens; > this 2011 paper seems to think so (bizarrely, I can't access it from > Oxford): > http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2818.1977.tb01136.x/abstract > > and this is site says lethal dose is 0.5-5g/kg: > http://cameochemicals.noaa.gov/chemical/4468 > meaning 2ml of a 0.1M solution contains 1/10th lethal dose...? (Someone > should check my maths...) [Coarse screens come mixed 2ml per condition.] > > > Has anybody done careful experiments that showed it really mattered for > a given crystal -- or even an entire screen? > > So I'm inclined to toss it out entirely rather than make crystallization > screening a "hazardous activity". (We're being subjected to a safety > review.) > > > Thoughts welcome. > phx ...................... Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry & Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://lupo.jhsph.edu
