Hi CCP4BB Forks,
In recently I got a membrane protein crystal in the quite normal
membrane protein crystallization conditions as other persons reported,
like PEG400 16-19%, pH 6.0-7.5, with 50 mM MgCl2 (in my case) by using
sitting drop method. These crystals are around 50-100 uM. They look
like trapezoid crystal. My problem is all of my crystals have not
diffraction in home source X-ray and just poor diffraction at
Synchrotron (lower than 20 A). My crystals like to appear on the
surface of the drop. Look like my crystals are quite light. I had
tried to use a needle to touch them. Unlike other protein crystal, my
crystal looks like quite "soft". When I touch it, it didn't crack, but
was bend or mashed. I had tried to do additive screen and detergent
screen. It seems they are not useful.
Do anyone have good ideas to optimization these crystals? Thanks for
your suggestions.
Frank
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