Hi Patrick
Did you mean that to go to BB? To put pressure on us....? :)
We've not done that analysis, no - good idea though. No standard
purification buffer, though most commonly it's HEPES pH 7.5ish, varying
amounts of NaCl and glycerol. Like most people, I assume.
There certainly are wells in the screens that are more prone to produce
salt - but all wells have produced protein crystals at some point, so
we've not thrown anything out. (I'm proud to be superstitious.)
That said: X-rays are cheap these days, just do the experiment! (My
view at least.)
HTH
phx
On 08/02/2013 09:46, Patrick Shaw Stewart wrote:
Good morning Frank
On a related idea, do you typically use a limited number of "buffers"
(buffer plus salt) for the final purification step of your proteins?
If so, do you have a chart of where salt crystals may appear in the
screens that you use most often? Could you put that chart on your web
site to help the community?
People could pick one of your standard buffer mixes to make their
lives easier later on.
Best wishes
Patrick
On 8 February 2013 07:18, Frank von Delft <frank.vonde...@sgc.ox.ac.uk
<mailto:frank.vonde...@sgc.ox.ac.uk>> wrote:
Test the diffraction - that's the only way. But given the other
junk in the drop, chances are they're salt.
(And don't post 5Mb attachments, please.)
On 07/02/2013 22:24, amro selem wrote:
Hallo my colleagues.
i hope every one doing ok . i did screening since two weeks . i
noticed today this crystals. i don`t know either it salt or
protein crystal . my protein has zero tryptophan so i could
distinguish by UV camera.
the condition was conditions:
0.1M SPG buffer pH 8 and 25%PEG 1500. in addition to Nickle
chlorid 1mM.
best regards
Amr
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