PCR DNA bands too large on agarose gel - (Feb/24/2015 )

Hello,

I have carried out gel electrophoresis for a construct that should be ~800bp. However, the DNA band spans from 750-950bp, instead of the usual thin line as the band. Why has this happened?

Thanks.

I'm guessing you have overloaded the gel, and have too much DNA in the band to make a sharp band. Try diluting 10x to 100x and trying again (or loading diluted samples in different lanes).