why should the conversion efficiency of competent cell be at least 10^8 cfu/_ - (Aug/28/2007 )
why should the conversion efficiency of competent cell be at least 10^8 cfu/μg DNA？
The required efficiency of competent cells is only determined by the concentration of the plasmid you are trying to transform. If you are simply transforming in a circular plasmid then a very low competency is required (e.g. if you transform 1ul of circular plasmid at 1ng/ul you into cells at 10^5 cfu/ug you will still get around 1000 colonies). If you are transforming a ligation, you will need a higher efficiency since the concentration of the circular plasmid is much lower, and likewise if you are doing something that gives even less circular plasmid (e.g. a complicated quikchange) you will need a competency of 10^10 or more.
thank u very much!