Re: [ccp4bb]: Xtals come out on the skin of drop surface

[Serge COHEN <cohen@embl-grenoble.fr>]

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At 1:27 +0100 15/12/01, OnLineHelpForm wrote:
>Dear all,
>
>Sorry for this non-CCP4 related questions but I sincerely hope you guys
>can help me out.  Recently I got my protein /DNA complex crystallized
>beautifully in PEG 1K or 3K.   However, these crystals are relatively
>small and stop growing when they just come.   In other words, I can not
>ever tell they are growing.    To my surprise, I found there is a thick
>skin on the surface of  drops and all crystals come sticking to that skin.
>It is said the skin forms out of  denatured protein.     So my question is
>how I can possibly make my protein happy in drops and hopefully facilitate
>their growing.     Any suggestions are highly appreciated.
>
>Thanks in advance,
>
>
>Aidong Han, hana@colorado.edu

Hi;

I had some drops with skin, in my case the skin was oxydation dependant.
i.e. if I had some anti oxydant (DTT, etc...) to th protein stock I no skin
(or it takes more time to appear).

As well, you can still get the Xtal from out the skin, indeed using
acupuncture needles, I first touch the skin at the root of the xtall to
detach it from the skin, and then use the needli to remove the skin. I
found it much easier to separate the xtal from the skin before breaking the
skin.

Serge.

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Serge Cohen.

PGP key id : 69B1D346
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