Dear Martin
You can either add the cluster as a powder, just dip the tip of a
needle in the powder and gently approach the drop with the needle, the
Ta6Br12 crystals will spray itself onto the drop. Then you just wait
for the crystal to turn green, I usually marked the position where the
powder had hit the drop, then mounted crystals lying with various
distance from the powder site. This was how we derivatized the Na,K
ATPase crystals (pH 7, 14 % PEG2kmme), with the H-ATPase crystal it
was a bit more tricky, the cluster would not dissolve that readily,
and one way to get around this was to dissolve the Ta6Br12 in water
(approx 5 mM) then use a speed vac to increase the concentration even
further. The highly concentrated Ta6Br12 will form a small round green
ball, that you can break with a needle and transfer a tiny droplet to
your crystal drop. The same approach was used with orange Pt ( Pt(II)-
terpyridine chloride)
best of luck
Preben
On 14/05/2009, at 20.29, Martin Jinek wrote:
Dear all
Now that tantalum clusters have been mentioned.... I have recently had
issues with the solubility of the Ta6Br12 cluster (obtained from Jena
Bioscience) in PEG-based crystallisation conditions at pH 8.0-8.5. Has
anybody also experienced this? Is there a trick to getting the
compound to
dissolve?
Best regards,
Martin
Jens Preben Morth, Ph.D
Aarhus University
Department of Molecular Biology
Gustav Wieds Vej 10 C
DK - 8000 Aarhus C
Tel. +45 8942 5257, Fax. +45 8612 3178
j...@mb.au.dk
website: http://person.au.dk/da/j...@mb
