We have sometimes used Michael Garavito's excellent suggestion of diffusing
glutaraldehyde into the drops - mentioned on this board a few days ago.
Our protein crystals either turned brown or turned into brown goo.
Michael and others, what effect would you expect glutaraldehyde to have on
DNA
It’s been my experience that protein crystals with that high a percentage of
tryptophan residues (>2%) should give a very clearly positive result from a UV
microscope such as a Jansi UVEX.
Diana
**
Diana R. Tomchick
Professor
Departments of
This is not at all conclusive, but one depressing thing is that DNA-only
crystals are often hexagonal (like yours are).
Can you reproduce them without the protein?
++
Phoebe A. Rice
Dept. of Biochemistry & Molecular Biology
The University of Chicago
Dear Kumar
you said 'shot from other conditions': we do not know then if you shot these
crystals or not.
Else:
- DNA should give you an X pattern, most of the time.
- protein should give you at least low resolution pattern, or faint rings if it
is powder pattern like
- salt should give you
Hi Joseph,
Are you having trouble getting bigger crystals. You said you shot them, and
they are not salt. Do they diffract at all? If they are diffracting to any
extent, you could optimize the crystallization condition to get better,
bigger crystals and shoot them. A simple way of growing fewer,
Hi Joseph,
Could you post the UV fluorescence image? Oftentimes, UV absorbing
objects that do not fluoresce (such as nucleic acid crystals) show up
dark against a brighter background in UV fluorescence.
V. Nagarajan
JANSi
On 6/19/2017 7:20 AM, Joseph Ho wrote:
Dear all:
I would like to
Dear Joseph,
I think, you already did the most classical test to determine what is in
your crystal.
Maybe you can try a destructive approach by washing the crystal prior to
put them in Agarose gel do a short run and color with ethydium bromide.
Simpler, you can also melt the crystal after
