Figure 1.

Display of fluorescein-labeled MseI CAG-containing DNA fragments from three pairs of monozygotic twins. Genomic DNAs were digested with the restriction enzyme MseI, ligated to adapter oligonucleotides of known sequence, and hybridized to an immobilized single-stranded probe containing (CAG)₁₂ repeats (see Materials and Methods). Captured DNAs were amplified by PCR with fluorescein-labeled primer 3 (Table 1) and displayed on an automated laser fluorescence (ALF) sequencing instrument. DNAs were from three pairs of monozygotic twins (pair 1, traces 15 and 16; pair 2, traces 17 and 18; pair 3, traces 19 and 20). The elution time (min) is shown on the x axis, and the fluorescence intensity is shown on the y axis (arbitrary units). The size range of the displayed fragments is ≈230 to ≈350 bp.