SNPdetector: A Software Tool for Sensitive and Accurate SNP Detection
Figure 3
A PolyA Bubble That Occurs in Multiple Samples
The bubble was recognized as a sequencing artifact by SNPdetector, and no SNP was called even though the alternative adenine residue (in the highlighted column) appeared in two samples with an average Phred quality score of 20. In addition, all three traces in this region have a polyG spill at the right, with a secondary guanine peak spanning four residues; and a polyT spill at the left, with a secondary thymine peak spanning three residues.