Exposure to light during crystal growth should not have any effect unless the fluorophore is destroyed by ambient light, which is unlikely.
V. Nagarajan JANSi http://janscientific.com -----Original Message----- From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Jacob Keller Sent: Thursday, May 14, 2009 12:42 PM To: [email protected] Subject: [ccp4bb] Crystallizing Fluorescent Molecules Dear Crystallographers, I have exactly two spherulite crystals of a protein-peptide complex which have a fluorescently-labelled peptide in them, and are therefore nicely colorful in both the light and fluorescence microscopes, making it easier to know that at least the peptide is in the crystal. However, they are not reproducible. Having gone through the usual list of possible variations which might account for the irreproducibility, I have hit the bottom of the barrel. I was thinking that since the original crystals grew in utter darkness, undisturbed for two weeks while I was away, they were able to nucleate. Is it possible that light exciting the fluorophores is detrimental to crystallization? Or perhaps the complete uniformity of temperature? Even microseeding from one of the spherulites produced nothing (except in the original well.) Any brilliant suggestions welcome... Jacob Keller ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program Dallos Laboratory F. Searle 1-240 2240 Campus Drive Evanston IL 60208 lab: 847.491.2438 cel: 773.608.9185 email: [email protected] *******************************************
