User manual

50 | Droplet Digital
™
PCR Applications Guide
Rare Mutation and Sequence Detection
Fig. 5.5. 2-D amplitude plot of a wild-type control well containing 5,000 copies/µl of an SNP assay
with no spray of false positives into the double-positive region of the plot.
Fig. 5.6. 2-D amplitude plot showing 0.002% mutant detection in four merged wells.
Figure 5.5 shows a 2-D plot of a single well with an assay for SNP KRAS G12V that
indicates no false positives at 5,000 copies/µl. This assay can detect 0.001% mutant,
or 1 mutant in 100,000 wild-type targets.
Figure 5.6 shows a 2-D amplitude plot of four combined or merged wells of
SNP KRAS G12V detecting 0.002% mutant.
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000
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0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000
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Interpreting 2-D Plot Results for SNP Assays
How does orthogonality affect assay performance? The shift of single-positive clusters
toward the double-positive region makes it more difficult to separate single-positive
droplets from double-positive droplets.