Hello. I am wondering if anyone can help me. I have been having PCR
problems for a couple of months. I have been having consistent smearing
with my PCR amplified product. A bright smear starts at my PCR product
and extends to my primers. Since my PCR product is large (2.8 KB) it is
a very large smear which extends to my PCR band. The smearing is also in
the negative control. I have replaced my Taq, my primers, dNTPs, etc...
to try to figure out what the problem is. Also, I am running a positive
control with DNA which has worked well in the past. I had the PCR
working with the same conditions and primers for about 2 months. Then, I
was sequencing for about a month and was not running PCR --- when I
started to run PCR again, I had the smears and have not been able to
resolve the problem. I have reautoclaved water, etc... Is it possible
there is something in my water source? What causes smearing? I would
appreciate any suggestions. Thank you. Cheryl
