Transformation efficiency and [DNA] - inhibition of transformation by DNA (Jul/06/2005 )

Can someone tell me why too much DNA inhibits transformation efficiency? Just curious...

Because DNA transformation efficiency is expressed as CFU per ug of DNA Generally if you use more DNA you will get more CFUs in absolute terms, but the transformation process is saturable (only so much DNA you can move into the cell).

You can get a reduction in absolute DNA CFU obtained if you use too much DNA, but this is often linked to contaminants in the DNA (10x more DNA = 10x contaminants).