I did double digestion for ERBB2 Wild type plasmid. I followed NEB protocols for double digestion. The erbb2 gene is inserted between XbaI and NotI. So i picked these two enzymes for digesting the plasmid to release the gene. But when i checked today i didnt find any bands in the gel. What could be the possible reasons ? Any one is having standard protocols for double digestion? please do send me in the mail