I have been doing DNA fingerprinting for the past few months by using RFLP method. I used a primer, which had been published on some journals, and followed their recommended PCR conditions. But after running the gel electrophoresis, i can only obtain smear for each lane, which were loaded with the amplicons, instead of getting some bands. I suspected my primer had degraded, thus i changed to another stock again. But the problem is still remain.