non-diffractable xtals!

[ewald]

Hi Folks!
	I was so desperate to get an answer that I didn't even check the
archives for this.  
	I have a xtal of a multimeric protein (final Mw of 80 kDa) which does
does diffract.  I have tried various additives to the precipitant and
have two-three xtal forms from those, av size 0.3 mm3/0.2mm3 app.  The
xtals do not seem to grow larger (hanging drop vapor diffusion).  The
xtals though look good but do not diffract beyond 10-12 A and even at
this low resolution do not give a good diffraction pattern. (15 deg and
cryo temperatures).
	How can I grow my xtals larger (if need be)?
	How do I make them diffractable? 
	Why don't they diffract at all? (apparently there are similar reports
suggesting xtal packing to be the culprit but I fail to understand how
such poor packing would make such good xtals- to the eye).
	Help please,
				Bhupesh. 7-10-99.

**********************
Bhupesh Taneja
Graduate student
Institiute of Microbial Technology
Sector 39-A
Chandigarh 160 036. INDIA.
bhupesh at lion.imtech.ernet.in
bhupesh at bragg.imtech.ernet.in
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