May be u could take a picture of your electrophoresis set up and attach. We would have a clear idea about it.

I am pretty sure, that the electrodes were placed wrong! Did your repeat the electrophoresis with the same samples? And why do you use such a high voltage? Cheers, Nadine

Repeat the experiment one more time. And if you get the same result you should check the buffer first of all. What is the source of your DNA(PCR product), ? Bacteria?plant?

Thank you all, it was the buffer concentration. I repeated it and this time worked.

Sure should be buffer because it would change the ionic charge.