ccdb toxin - (Jul/30/2014 )
Thats what I ment..
I know how the gateway system works...
The ccdA should not be present on that particular F plasmid...
The F plasmid is almost never complete when used in cloning (in strains)
phage434 on Thu Aug 7 14:53:43 2014 said:
I've never tried ccdB with an F' strain. I avoid those strains, since most have additional resistance genes that get in the way of routine cloning.
You are right.
I just do not buy them because they cost more and I do not need the F episome.
And see below.
BioMiha on Thu Aug 7 16:35:40 2014 said:
ccdB is the toxin and ccdA is the antitoxin. So if ccdA is present on the F' episome they won't be selected against even if they haven't taken up your insert. That's why you see background.
Its good that I am a bit picky and always checking things rather than just depending on others all the time.
It turns out they do contain this antitoxin! Pretty weird life science says on their website its not for ccdb propagation... I assumed they removed it from the F episome (since its not the complete one... but they give hardly any details about it).
So you are right, its not good to use them!
Pretty funny, they have been using them for a while...good that I checked everything.
Will save me a lot of fuzz.
Glad to hear you've managed to make sense of it all. The F' episome is so big that they rarely write it all down, so even if the gene you're looking for is not specifically written, it might still be there. I doubt that they've re-engineered the episome, I reckon it's all there they just don't tell you.
BioMiha on Mon Aug 11 10:39:14 2014 said:
Glad to hear you've managed to make sense of it all. The F' episome is so big that they rarely write it all down, so even if the gene you're looking for is not specifically written, it might still be there. I doubt that they've re-engineered the episome, I reckon it's all there they just don't tell you.
yeah, but they should not mention its not for ccdb propagation...
Ok granted: the antitoxin is not 100% , but stil.. do not mention it on your website.
I realize I'm late to this party but FYI, Top10 F' cells do contain the CcdB operon and have been used in studies for propagation and analysis of ccdB (Ex: http://mbu.iisc.ernet.in/~rvgrp/PDF/80.pdf). IIRC, the reason they are not recommended for propagation of CcdB plasmids is that while CcdA allows for survival in the presence of low levels of CcdB, the lack of the gyrase gyrA462 mutation means that if levels get high enough (say from a CcdB selection-based cloning vector), they will still die.
Yeah, I know, but thanks for the paper.
Personally the life technology website is not that clear about it.