Hi,

I had a similar story like yours.Then I added a drop of 10ul simulated mother 
liquot which contains much higher concentrations of all components in the 
normal mother liquot. Sometimes, the crystals attached to the plastic would 
float to the  surface. If not, take another  10ul, but blew it to the bottom 
plastic with a pippetman back and forth, and some crystals would also leave the 
plastic(But you have to be very careful to do this.)

My friend Jill solved her similar problem by hanging drop setup instead of 
sitting drop.

Good luck.

Deliang


  ----- Original Message ----- 
  From: Savvas Savvides 
  To: CCP4BB@JISCMAIL.AC.UK 
  Sent: Tuesday, January 27, 2009 3:05 PM
  Subject: [ccp4bb] sticky crystals


  Dear colleagues,

  we have been growing crystals of a protein complex  in sitting-drop geometry 
that stick to the bottom of the drop remarkably well. It's as if they are glued 
onto the plastic. This makes crystal handling next to impossible without 
destroying the crystals. We have tried whiskers, loops, all kinds of 
micro-tools, and pipetting techniques to no avail.  I can say at the outset 
that we have been unsuccessful in growing these crystals in hanging-drops or at 
4 degrees. Deglycosylating the complex also leads to nowhere. In fact, we are 
only able to get crystals from homogeneously glycosylated protein produced in 
HEK293S/I- cells. 

   

   In the meantime we are playing with the idea of  siliconizing the 
sitting-drop depressions to alter the crystal/plate interface. But then again, 
nucleation events on the plastic  may be the reason we are getting crystals in 
the first place. We have also thought of trying microseeding to have more 
control on nucleation issues. Our protein production is quite limiting and 
forces us to be very selective with our experimentation.

   

  Nonetheless,  while we are waiting for fresh material  to explore some of 
these ideas we would like to make the most out of the crystals we have grown 
thus far. We would therefore very much appreciate any input/ideas on 
manipulating these crystals for data collection.

   

  Best wishes

  Savvas

   

   

  ---- 
  Savvas Savvides 
  L-ProBE, Unit for Structural Biology 
  Ghent University 
  K.L. Ledeganckstraat 35 
  9000 Ghent, BELGIUM 
  office: +32-(0)9-264.51.24 ; mobile: +32-(0)472-92.85.19 
  Email: savvas.savvi...@ugent.be 
  http://www.lprobe.ugent.be/xray.html

   

   

   

  From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of 
Katarina Moravcevic
  Sent: Tuesday, January 27, 2009 10:52 PM
  To: CCP4BB@JISCMAIL.AC.UK
  Subject: [ccp4bb] pseudo translation

   

  Hi all,

  here is a question from a beginner. I have a home source data set  that 
indexed and scaled in a P2 space group  (a=46.704,b=59.362, c=48.783, 
alpha=90.0, beta=104.469, gamma=90.0) with predicted 2mol/au. After failing to 
get a MR solution with Phaser I ran the phenix.xtriage which showed that I have 
a large (89.18) Patterson peak at 0.5 0 0.5 which indicates pseudo 
translational symmetry. I was wondering if there is anything I could do with 
this data to get around this problem. Given that I don't have a lot of 
experience any suggestion/explanation would be fantastic. 

  Thanks in advance

  K





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