This may not apply in your case but it is not uncommon for a protein to "precipitate" in a microcrystalline shower when put in cold. Once it worms up, the crystals dissolve and the precipitate clears up. It is easy to check under a high magnification microscope. Cheers, N.
Ruslan Sanishvili (Nukri), Ph.D. GM/CA-CAT, Bld. 436, D007 Biosciences Division, ANL 9700 S. Cass Ave. Argonne, IL 60439 Tel: (630)252-0665 Fax: (630)252-0667 [EMAIL PROTECTED] -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Joe Sent: Tuesday, November 13, 2007 2:30 PM To: [email protected] Subject: [ccp4bb] DTT sensitive? Hi there, I see enormous precipitate of my receptor protein when I take it out of freezer. But all the precipitate dissolved quickly after I added 1mM DTT to the solution. Does this mean that some surface Cys are causing problem? Or why is the protein so sensitive to DTT? Anybody experienced this kind? Any advice is appreciated. -Joe
