FIGURE 9.23 Sequencing by ligation uses short fluorescently labeled oligomers that hybridize in short increments if they are complementary to the DNA template. The template DNA anchored to a glass slide is flooded with fluorescent-labeled oligonucle-otides. If the oligo is complementary to the template, it is ligated, and then two bases are detected at a time. The oligonucleotide is cleaved, followed by the next round of ligation. Each time, two new nucleotides are detected.