Dear Aisyah,

You should observe at least one clear Band for your Marker.

If all of your probably Bands were negative so you should repeat again your Nested PCR.

If you even did'nt see the marker band, maybe you have connected the cables from the wrong side ?

If your nested PCR failed to produce a band it is highly likely that the band you purified from the initial PCR was result of non-specific amplification. Do you have a picture of the gel for the inital PCR....and/or any other information to share?

Hi, thank you so much for your answer. I and my team just make an evaluation for our research. we assume that the problem because we put wring sample for nested PCR that we did. so it's finally solved. but i really appreciate for your help. this discussion giving me many information about PCR :D