How to get rid of PCR primer dimer - (Mar/17/2003 )

Hi guys,

Few months back,my primers were working good.Now I am seeing a band for my negative control (No DNA) far from the 50bp band even for new set of primers.I thought that is primer-dimer band.So I tried my NC PCR with different mg2+ concentrations(1mM to 2.5mM),reduced the primer concentration from 0.5uM to 0.25uM,different DMSO concentrations(2.5%,5%,7.5% and 10%) and annealing temperatures (My primers annealing temperature is 63C...So I tried from 62 to 70).Actually when I tried my PCR with 72C I did not see that primer dimer band.But I did not think I can get my expected result with 72C.

Can you guys suggest me what else I could try?I think I have tried pretty much all the suggestions that you gave on this thread.

Thank you!!

Hi, medchemgirl...

I'm noreen..Ive been doing RT-PCR works n my PCR doesn't turn out to be so good..I've come across your comment n u r having gud results using DMSO..what are the concentration of the DMSO n when did u put it in the pcr reaction..thanks..

Hi guys!
I am facing the same problem of primer dimer....I have designed my primers recently for Mycoplasma detection, but the primers have different annealing temp and also dont find any bands at expected bp length?

am new to this forum! so any suggestions are welcome

There is a product that I use called PCRboost. Its from a company called Biomatrica. I just put this in my PCR reactions that I want better results with. Its great. I ran a comparison side by side and I can see a very noticable increase. It also helps with primer dimers, so I thought it might help you with your problem as well. Hope this helps!

Austin