Phred score

A Phred score is a number that indicates the confidence or accuracy of a specific DNA base call made during sequencing. It reflects the probability that the identified base (A, T, C, or G) is correct. Higher Phred scores mean higher confidence; for example, a score of 20 suggests a 1% chance of error, while a score of 30 indicates a 0.1% error probability. Essentially, the Phred score helps scientists assess how reliable each part of the DNA sequence is, guiding them in analyzing genetic data more accurately.