-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear Maria,
this is similar to the condition I used for my PhD thesis. I suppose the following happens: when you mix the drop the protein crystallises by inverse salting-in because you dilute the high-salt concentration. This happens instantaneously and you are lucky enough to observe crystals. As you leave the drop overnight you are observing the opposite from what normally happens: your drop gets larger instead of smaller because the hygroscopy of the 150mM NaCl is stronger than that of 2.5% PEG8K and you further dilute the drop so that the crystal disappears. Check if your drops get bigger overnight to check if my assumption is correct. During my PhD I worked with 0.5M NaCl and maybe I am wrong that 150mM NaCl is stronger than 2.5% PEG8k. Best, Tim On 05/02/2014 01:39 PM, dusky dew wrote: > Dear All, > > I am trying to crystallize a protein with Adenosine. My protein is > in 20 mM Tris, 300 mM NaCl and the crystals appear in a condition > with 5 percent PEG8K, 0.1 M Sodium Cacodylate. The protein is > incubated with adenosine for 1/2 hr before setting the drop. The > crystals appear right after the drop is set but unfortunately they > dissolve overnight. The plate is kept at 16 degree. > > Could anyone elaborate on this. Is it possibly occurring because > Adenosine has stability issues. > > Thanks for your suggestions. ~ Maria > - -- - -- Dr Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Icedove - http://www.enigmail.net/ iD8DBQFTY4gDUxlJ7aRr7hoRAvZcAJ9fnqKmsjWvsvQifgB2oG3EH4/h9wCghJVA 9Ng4dZzXQG5+LQiPwZVdXXQ= =LbR6 -----END PGP SIGNATURE-----
