Hello everyone.
I remember the screen was again from Jenabioscience and this had happened
with one of my protein. The screen was very old and the condition was
peg3350, tris pH 8, lithium sulfate and NaCl as the salt. Hit was obtained
which was never reproducible. Luckily I solved the structure
?Hi Jonathan,
Hopefully you know about the trick of making any precious condition last longer
- use the 'magic' solution only in the drop itself, and use the best
approximation you can make in the reservoir of the experiment (if you are doing
vapour diffusion)
Regards, Janet
Janet Newman
Hi Jonathan,
Old buffer may have slow evaporation with some side reactions. The
concentration of each component may increase a little bit. In this case,
I would consider the condition as the origin for further optimization.
Each component may need to be considered separately.
For 150mM Tris
Jonathan,
While your claim of oxidative degradation of PEG1000 may be true -- I gather
you mean that the conversion of the ends of the PEG polymers to aldehydes or
peroxides, then to carboxylates -- you should check out Fran Jurnak’s old
paper (Journal of Crystal Growth 76, 577, 1986). The
Hello,
Such pH drifts are rather common with crystallisation screens. Have you tried
to produce other precipitant solutions with ca. 47% PEG 1000, 80 mM Potassium
bromide but having a pH of (say) 6.2 ? A pH rangle close to that where your
crystals were obtained. This would mean changing
