Yes, This is 95% likely to be the dreaded T1 phage (well, OK - any lytic phage that infects your culture, really). The almost-only other alternative is that your protein lyses the cells.
Dealing with phage infection can be tough especially in the multi-user environment and doubly so if you make your own competent cells... Artem "Nothing is built on stone; all is built on sand, but we must build as if the sand were stone" Jorge Luis Borges -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Jacob Keller Sent: Thursday, July 02, 2009 11:42 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Shredded E coli pellets Dear crystallographers, I recently expressed some new constructs, and found after my usual expression protocol that the cell pellets were not compacted at the bottom corner of the bottles us usual, but were instead smeared as a film on the side, and further, were somewhat clumpy, like clots, and with a smaller pellet in the usual location. The centrifugation was exactly as usual. I noticed that there was also a bit more foam in the medium than usual, but I am not convinced that this was the issue, although it might be a symptom. My suspicion is that the constructs are lethal and cause cell lysis, but I am not sure. Has anybody seen this phenomenon before, and gotten to the bottom of it? 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: j-kell...@northwestern.edu *******************************************
