Hi Joel,

Could you give us some more detail on your procedure?

I suppose you are cloning using restriction sites.  Is your fragment derivingfrom a enzymatic digestion? Did you dephosphorylate your vector?

Piero

Hi Piero,

Thanks, yes i can. I'm cloning using cohesive restriction sites with XbaI and BamHI restriction enzymes.  No, i don't dephosphorylate your vector yet. 

You need more details?

Joel

" I always get self-ligation of the vector" ... adding the dephosphorylation step could help to lower down the background.

One more question, your insert come from a PCR reaction?

Yes i know, i didn't have this resource, but i will try soon as possible. Yes my insert come from a PCR reaction but i do a purification of PCR