beginnergenetic

Hello: I'm new in the forum. I hope someone could help me. I have a couple of samples of DNA aislated from a protozoan parasite 1 year ago. I did various PCR successfully. Now I have done some more PCR with the same DNA samples and same primers, all conditions are the same as in the past but, nothing work. I can't get good results. Someone has any idea what could be happening? My primers were diluted again for trying new PCR but nothig work. Help!!!!