On Wed, Jun 23, 2010 at 12:40:35PM +0530, R.Srinivasan wrote: > Dear All, > > I have got initial crystals in a condition with PEG 1000. The PEG > 1000 stock we had in our lab was rock solid and when i heated it to > about 50 degrees for 15 to 20 minutes it became a solution. We > thought the compound has got out dated or something like that and > bought a brand new bottle from Sigma and this is rock solid too. > > Is this something characteristic of PEG1000? The hit condition says > its 12.5% w/v PEG 1000 but it apparently seems i could never get a > powder of it. > > So my question is, Can i go ahead using this melted solution form of > PEG1000 for setting up optimizations? Since mass is temperature independent you can use the PEG1000 solution to weight 50mg and dissolve it in 50-80ml water, let it cool down to room temperature and top it up to 100ml (with water). I think this way you created a 50% w/v stock solution of PEG1000 which you can further dilute to set up the desired concentration.
Tim > > Thank you all in anticiaption, > Vasan > > -- -- Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A
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