In addition to all the excellent suggestions to perform seeding, you could also
try sitting drop vapor diffusion, and also different temperatures. Sometimes
moving from 20 to 4 degrees does the trick.
Diana
**
Diana R. Tomchick
Professor
Hi Nikolaus
I completely agree with Claude's comments. Microseeding is the first thing
to try. You would like to find conditions where you *don't *get crystals
without seeding, but you *do *get crystals with seeding. Then, just by
diluting the seed stock, you can control nucleation. Look at
Le 09/09/2019 à 17:22, Nikolas a
écrit :
Dear
crystalgrowers,
I am
currently working with a protein that appeared to be
friendly but turned out it was not the case.
I
Hi Nikolas
The first thing I would try is to solubilise the protein a bit more, maybe by
adding a few % (1-5%) glycerol or ethylene glycol to the growth conditions when
you set up the drops.
The next thing would be to experiment with ratio (protein:precipitant) and drop
size.
Lastly, trial
Dear crystalgrowers,
I am currently working with a protein that appeared to be friendly but
turned out it was not the case.
I found myself to face -in the scale up- the opposite of the usual problem
of nucleation (I really love how this topic finds new ways to make fun of
me). In 24-well plates,
kellydaugh...@gmail.com
To: CCP4BB@JISCMAIL.AC.UK
Sent: Wednesday, January 22, 2014 9:47 AM
Subject: Re: [ccp4bb] Intergrown crystals
Klaus,
I've had success with using paratone to separate crystal clusters. Paratone is
quite viscous, and an excellent cryoprotectant. By dragging your crystal
Dear ccp4bb contributors,
We are dealing with the problem of a protein (~ 50 kDa) that crystallises
readily, but has an annoying habit of forming highly intergrown rods or
needles.
Even when the crystals look optically homogenous under the microcsope,
diffraction is so so (3.5 Å or so on the
a
combination of micro-seeding with broad screening
Good luck
Thierry
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Klaus
Fütterer
Sent: Wednesday, January 22, 2014 10:02 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Intergrown crystals
Dear ccp4bb contributors,
We
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Dear Klaus,
this list seems to be missing means to reduce the growth rate, in
particular micro seeding applied to a matrix screen of protein vs.
precipitant concentration:
Find the condition(s) just below crystals form and micro-seed with a
cat
Klaus,
I've had success with using paratone to separate crystal clusters. Paratone
is quite viscous, and an excellent cryoprotectant. By dragging your crystal
around (gently) through paratone you can sometimes isolate a single crystal.
Also, do you have access to a micro-focus beam? You could try
Klaus,
You say that crystallises readily
So you have solved your own problem. You need to control the rate at which
the crystals grow.
Among all the things you have tried already, you may have the answer
regarding how you can
control the crystal growth rate so as to slow it down enough as
Dear Klaus,
Using 250-500 miL of AL's oil ( 1:1 mixture of paraffin and silicone oil)
to cover your well solution (in case u are using vapor diffusion) or even
~10 miL of oil on top of your drop can help to reduce nucleation rate and
provide single crystals of higher diffraction quality.
My two
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