High throughput sequencing data is often presented in the .fastq format. This flat text file format contains both the nucleotide sequences and Phred quality scores(Q scores). Quality scores estimate the accuracy of each nucleotide.
| Phred Quality Score | Estimated Accuracy |
|---|---|
| 10 | 90 % |
| 20 | 99 % |
| 30 | 99.9 % |
| 40 | 99.99 % |