On Tue, 2012-05-15 at 15:51 +0100, RHYS GRINTER wrote:
> A colleague suggested that sulphate or phosphate could fit at these
> distances, but these ions have not been added at any stage of the
> crystallisation process.
>
I vaguely remember a report about 2-3 years ago at the ACA meeting of
phosphate contamination of PEGs from certain manufacturers. But why
would phosphate (negatively charged) bind at the site that seems to
attract calcium (positively charged)? Potassium?
Check if you have a peak at that position in anomalous difference map.
Maybe ICP-MS can give you an answer.
--
I don't know why the sacrifice thing didn't work.
Science behind it seemed so solid.
Julian, King of Lemurs
