| | Re: full length gene isolation.
Are you amplifying from a plasmid, genomic DNA, or other?
The bright band next to the well is most likely your template - i.e. genomic DNA or a plasmid.
Smears are usually due to excessive amounts of template; low-affinity interactions between primers and template occur under these conditions, leading to all sorts of amplifications occurring. Reducing the concentration of template should help with that.
Another possibility may be template degradation (if your template is old, or not stored properly). You may need to make a new stock of template in this case.
Lastly, you may have some contaminating DNA. This usually comes from the water you use in the PCR reaction. Make sure you're using molecular-grade water.
Hope this helps