Distinguishing mutant sequence in heterozygote?

[Gregory Jacobson]

   I am analysing tumours for p53 mutation type using PCR and automated
sequencing.  My electropherograms of an exon five sequence show concurrent
peaks - indicative of a mutation against a wildtype background?- at places
along the sequence.

  I would be grateful for suggestions of an efective methodology for the
distinguishing of mutant sequences (represented in approx. 10% of cells in
each sample) against a wildtype background.

 Thanks in advance,

    Gregory Jacobson
    1st yr MSc student
    Uni. of Waikato
    Hamilton
    New Zealand