how to improve resolution

From: LISA
Date: 6 January 2012 14:38

Hi all,

I have a DNA binding protein. I get crystals of this protein by co-crystallization with different dsDNAs. But all the crystals have very poor resolution, about 10-20A. I tried to purify protein-DNA complex before setting trays, but it didn't work.The shape of my crystal is not bad.  Please give me some suggestion. Thanks.

lisa

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From: Cale Dakwar

Hello Lisa,

Could the 10-20A be a result of cryo damage as opposed to true packing disorder?  (try collecting a few images at room remp)

If its cryo damage, improve your cryo / try different cryoprotectants.

If its not cryo, just screen about a thousand different crystals from around the same conditions as is giving you 10-20A.  There will undoubtedly be some in there that are much much better - I'd say even better than 3A.

Cheers,

C