Proportion of colonies containing DNA inserted at the cloning site - (Mar/08/2011 )

Hi, when inserting a DNA fragment into a bacterial plasmid and and left to grow in lets say Ecoli as usual! I know the proportion of colonies containing DNA inserted will be about one quarter but why?

Thanks everyone

Actually it depend on the insert and vector size, how you prepare the DNA, the ligation strategy, ligation conditions, toxic expression of the insert and possibly the secondary structure of the insert molecule.

The efficiency of ligation can vary from 98% to 0%.

In other words, the efficiency can vary alot, for many reasons.