Linearising plasmid before transfection? - (Oct/15/2012 )

Is there a need to linearise a circular plasmid DNA before transfecting it into a mammalian cell with Lipofectamine or electroporation? Or the circular form will integrate into the host cell automatically?

http://www.protocol-online.org/biology-forums-2/posts/6156.html

http://www.protocol-online.org/biology-forums/posts/6793more1.html

http://www.protocol-online.org/biology-forums/posts/5619.html

http://ko.cwru.edu/protocols/DavesNotes3.html

There is no need to linearise. But if you do, the advantage is that you don't disrupt your gene, promoter and resistance.