What’s wrong with my NTC - (Sep/09/2010 )

My NTC always has a band which is the same size as my product(about 150bp). Maybe contamination……but I changed everything for PCR, including master mix , water and primer……I can still see the band ,it has been for several weeks ,my god ,help……

If you've already done everything under the sun to clean up your reagents and still get this band in your NTC, then there are two possible things you can do:

1. Buy new primers. This background band could well be your primers coming together in some weird structure that happens to run at this size
2. Design a new assay. Having a band at 150 bp is very close to where all the issue arise. Design an assay that gives you a larger band, at least 300 bp.

My two cents

thank you ivanbio
but what's the size of the pds?there are two bands in my NTC,one is primer dimer, the other is weird structure ?