gel smear without stop

[Shi-Jye Chu]

Hi:

   I had no too much experience in pcr, Recently I try PCR and run gels
that showed  smear without distinct stop and no visible band. I check the
book for pcr that you must optimization experiments.Only change that is
difference from bewfore is using Taq from PE company.  How can I do ?
  the following the my methods

10x pcr buffer( P.E company)   5 ul
MgCl2(25mM)                    3ul
DNTP(2.5mM)                    2.5ul
5' primer( 20uM)               2.5 ul
3' primer(20um)                2.5ul
H2O                            32.5 ul
Taq( 5U/ul, PE company)        0.3ul
CDNA temple                     2ul




S-J