I am working with a line of BL21(DE3) cells that contain a pET14b vector w/1.2 kb insert, resulting in the top band you see that is ~6kb. The band directly below it is the pLysS plasmid (~5kb) that is in the DE3 line. I had to run the gel forever to separate them as I only want pEt14b.
What might that third band be? It is ~3kb according to the 1kB DNA ladder I am using.
Really curious as to what others may think, Thanks for reading!