bitscore

Bitscore is a term used in bioinformatics to describe the score assigned to a sequence alignment or a sequence similarity search result. It is a measure of the statistical significance of the alignment or match, indicating the likelihood that the observed similarity is due to chance rather than a true biological relationship. The bitscore is calculated using a scoring matrix, such as the BLOSUM matrix for protein sequences or the PAM matrix for DNA sequences, and takes into account the length of the alignment and the frequency of the amino acids or nucleotides involved. A higher bitscore indicates a more significant match, while a lower bitscore suggests a less significant or more random match. Bitscores are commonly used in database search tools like BLAST (Basic Local Alignment Search Tool) to filter and rank search results, helping researchers identify biologically relevant sequences from a large dataset.