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
>
>
--
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Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
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