Dear Mahesh,
cross-seeding into other conditions often works but still the chances
are much lower than seeding the same form.
Best wishes,
Matthias
(Please desist from sending so large attachments to half the planet!)
-----------------------------------------
Dr. Matthias Zebisch
Division of Structural Biology,
Wellcome Trust Centre for Human Genetics,
University of Oxford,
Roosevelt Drive,
Oxford OX3 7BN, UK
Phone (+44) 1865 287549;
Fax (+44) 1865 287547
Email matth...@strubi.ox.ac.uk
Website http://www.strubi.ox.ac.uk
-----------------------------------------
On 1/17/2014 10:24 PM, Mahesh Lingaraju wrote:
Hi Folks
The protein that I am working on gives several initial hits which are
needles. And at random, I picked the needles from a condition (0.2 M
cacl2, 0.1 M HEPES pH 7.5 & 28% PEG 400) and seeded into another
screen where I added 1µl protein + 1µl reservoir solution + 0.3 µl
seed stock. I prepared the seed stock fresh by adding 36 µl of the
reservoir solution to preexisting 2µl drop.
One of the conditions from the seeded screen gave me a hit that looks
really promising ( see attached). I am sort of positive that these
crystals are protein as they are UV active.
I tried to reproduce these but with needles from another condition
which actually look much nicer than the seeds i used to produce these
crystals. However, I failed to do so.
While i understand that seed quality is important, I find it
interesting that the crystals do not reproduce with similar or better
looking seeds. Is it common that the seeds absolutely need to be from
the same condition to reproduce hits ?
thanks for any suggestions
Mahesh