Analysis of a p53 mutation by PCR direct sequencing using fluorescent termination nucleotides. A chromatogram of control DNA is shown in (A). (B) and (C) correspond to chromatograms of the PCR product of exon 8 of p53 from a mutated case sequenced from both ends. A single base pair substitution (G → T) was detected in this case. Arrows point to the site of mutation. Note that the signal corresponding to the germline nuleotide could not be detected.