The 8 amino acid comparison search is based only on the criteria of exact residue matching to an 8 amino acid length in a COMPARE allergen sequence. Similar to the 80-mer search, an 8-mer search begins with the process of breaking down an input sequence into its composite 8 amino acid length sections. Each section, or 8-mer, is then a query input sequence for separate algorithm and database comparison that reports any exact matches with allergen(s). There is no E-value utilized for examining alignments and FASTA is not involved in this process.
A match is referred by Codex Alimentarius (2003 and 2009) as a type of short-length, exact match bioinformatic alignment that may add value to understanding relevant alignments between novel or new proteins and allergen sequences. This type of search has been shown to possess a high degree of false positive outcomes in alignments due to the short length and non-specificity to allergens compared to non-allergens.(Silvanovich et al., 2009)