PCR....help

[FS300512 at yusol.bitnet]

Recently we are experiencing problems with our PCR reactions.
One day the reactions work fine, the next day, if we repeat the same
reactions (everything the same) they just don't work. It does not
depend on the person who does it. We use a Perkin Elmer machine and Cetus
or Pharmacia Taq and amplify an approx. 2000 bp piece. Does any one
have ideas about the reproducebility problems more people must be
experiencing?

Thanks!
Johan de Boer
FS300512 at YUSOL.BITNET