4Mb attachments, posted to a mailing list???? NOT COOL.
On 24/07/2012 14:40, Niks wrote:
Dear All,
I am trying to crystallize a recombinant dehydrogenase protein. Got
five hits in PEG ION Screen from Hamptons (20% PEG 3350 with 0.2M
Sodium Acetate, 0.2M Potassium acetate, 0.2M ammonium acetate, 0.2M
sodium formate and 0.2M Potassium Chloride) after two days.
Crystals looks like needles most of time, sometime broader needles
(Pictures attached). UV crystal scanner says those are protein
crystals, but when we tried to pick up one and shoot at room
temperature, diffraction patterns looks like similar like of powder
diffraction (picture attached).
I have tried 50 of the 96 additives(whichever I can arrange
of) mentioned in the additive screen from Hamptons . I have tried
detergent screen from Hamptons (this time original screen solutions).
I have tried incubating the plate at 28degrees as well
as 10degrees, Though waiting for 10degree results but one drop showed
needles again after normal two days of growth period.
I tried to slow down the supersaturation by adding 100ul of 1:1 ratio
of silicon oil and paraffin oil over the 1ml of well solution. This
time no crystals but some precipitation.
If anyone spare any word of wisdom to improve these crystal quality, I
will be very grateful.
If seeding is the only obvious thing to try, any reference for the
seeding procedure will be highly appreciated.
Thanks very much
Nishant Varshney
PhD student,
National Chemical Laboratory,Pune,India
--
"The most difficult phase of life is not when No one understands
you;It is when you don't understand yourself"
