depending on the importance of the project, I would be tempted to just
wait for the crystals to grow, and in the meantime:
- work on another project
- start a new project
- write a grant application, a paper, a review...
or a combination of the above.
Mark
Quoting William Scott <wgsc...@chemistry.ucsc.edu>:
Dear James:
It is extremely hard to make generalizations, but if it takes months for
crystals to appear, the following questions are worth asking:
1. Is the actual concentration of macromolecule, precipitating agent, etc
required for crystallization higher than what you are using? A closed
vapor diffusion chamber is somewhat permeable to water vapor, and in the
course of five months, you could easily lose half of the water. Try
doubling the protein concentration, or crank up the concentration of one
or more components in the reservoir solution.
2. Is the actual macromolecule you crystallized the same as what you
started with? Slow degradation, or proteolysis, may be taking place, and
the crystals you are growing are something else. (Similarly, if you have
a cofactor or coenzyme, as these could slowly decompose into the critical
ingredient for crystallization).
3. It might be too cold, and warming things up a bit might speed up
crystallization.
Hopefully that will get you started before the experts reply.
Bill
On Sun, October 11, 2009 8:27 am, james09 pruza wrote:
Dear crystallographers,
Sorry for the non-ccp4 query. I am new to this field and need some
suggestions. My question is, why some protein takes longer time to
crystallize, say 6-8 months, and it is the only condition to get the
crystals.? What are the ways to get the crystals faster.
The crystal appears with 60% of 2-Methyl, 2-4 Pentane Diol and only at 4
degree with very low concentration of NaCl. I have got some of the
sugggestions earlier from the CCP4-discussion board for microseeding, but
it
did not work.
All suggestions from the experts are welcome.
Thanks.
James
William G. Scott
Contact info:
http://chemistry.ucsc.edu/~wgscott/
