primer-dimer on re-PCR ?

[Mati Reeben]

Hi everybody,

It could be a FAQ, but still I would appreciate very much, if smb. can
give an explanation of the following phenomenon.

I make PCR from genomic DNA. Looks good, no primer-dimers. Then, to get
enough material for sequencing, I make re-PCR from the band from gelslice
(I freeze-thaw the ethidium bromide stained gel piece with the band). I
get the necessary band, but also a lot of primer-dimers. The scale up
this way is not good enough. What could be the problem ? I can not use
the initial material for scale-up as it is limited.

Thank you in advance for any help and I would really appreciate the
answers to be also personally mailed to me.

Yours sincerely,

Mati Reeben