I had to run a gel electrophoresis at college with an undigested pUC18 (all the way left), digested pUC18 (lane 7) and a digested version (lane 8) in which i inserted a fluorescent gene (pET Biotin mOrange).

according to my other samples on the gel the inserted gene did not get transformed into the plasmid correctly. So there is no gene insert. My teacher confirmed this with me.

But we are both stumped on lane 7 and 8 where it should have had 1 band of 2.5 kb and 2 bands with 2.6 kb and 0.75 kb.

If the orientation reversed for lane 8 the bands would be 3.3 kb and 57 bp big, this is not the case either.

We only used 2 restriction enzymes BamHI and HindIII, if only one enzyme was functional in the digestion there would still be only 1 band for both lanes.

But because my teacher confirmed that I have no insert gene lane 8 should be identical to lane 7 on my gel.

Me and my teacher both do not know what caused lane 7 and 8 to have 2 bands, we were hoping that someone here would perhaps know or maybe point us in the right direction.