Microbiome Profiling by Illumina Sequencing of Combinatorial Sequence-Tagged PCR Products
Figure 5
Quality scores for all overlapped 120 bp composite reads.
The scores a log-odds score of the likelihood of error in the base call, higher scores represent lower likelihoods of error [40]. They are expected to decrease with distance from the left or right sequencing primer, and to be highest in the region of perfect overlap because scores are additive.