I'm getting dark blue colonies and lawns when I'm plating E. coli cells transformed with plasmid containing E2 Crimson as the gene of interest under high copy number origin of replication and constitutive promoter in both LB as well as M9 agar plates. Similarly after centrifugation of such cells, I get dark blue pellets of the live cells.
Can anyone explain why I'm getting such blue colonies/lawn/pellets? If anyone can direct me to any literature mentioning such observation will also be extremely helpful.
Hi
we have sometimes green colonies and green cell pelets with E.coli bearing a plasmid with the GFP gene under a T7 promoter (there is some transcription leaks even in bacteria not expressing the T7 polymerase as DH5alpha) so I would not be surprised having colored E coli bearing Crimson under a constitutive (bacterial) promoter ... however E.crimson is supposed to be a far red emiting fluorescent protein so I suppose there is some other factors to get dark colonies
Hi Didier Poncet, thank you for your response!
We also get green colonies and cell pellets with GFP but like you said E2 Crimson is supposed to be a far red emitting fluorescent protein so getting blue colonies and pellets with it is something we are finding hard to explain.
- Badges
- Science topic