I have done my PCR, the expected PCR product size is 772bp (right size,right gene), and I also did cloning and sequence as well. What happened is ?I have extra band (172bp), I blast the sequence on NCBI but I cannot find any similarity. however, from the sequence, I found the forward and reverse primer switch the location, which means my forward primer flip over and located in the end of the sequnce and the reverse one jump to the bigining of the sequence. I also blast the midlle section of the sequcece. I could not find it in the receptor and any other genes.
Can anyone give some commment for the situation?