transformation colony - how to get rid of background colonies? (Sep/28/2005 )

hi all,

what are the factors that produce background colonies on our transformation plates? and how to avoid that to happen?

thanks.

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If you speak about satellite colonies they are usually obtained when all the antibiotic has been used up
If you plate too many cells they produced Beta lactamase after their dstruction (if not resistant of course) and that reduce the positive as well.

Ampicilline is known to be less efficient than other analog antibiotic you can substitute Carbenicillin instead of Ampicillin but it's very expensive Unfortunately !

If you talk about non ligated colonies they usually comes from a supercoiled contamination of the CIP vector and then you have a lot of negative colonies cause the vector is supercoiled and produce much more transformants than a ligation (approximately 100 times more)

Hope it answer your question !

Pesji

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If your vector is cut with only one Restriction enzyme then you have more chance of vector getting religated which leads to colonis on your control plate.(empty vector will have ab resistance) Best way to avoid this is to Dephosphorylate(CIP treat) your vector.

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