The Nullomers Database is a web-based resource which aims to facilitate exploration of biological nullomers (a.k.a. minimal absent words). Its purpose is to catalogue and enable sharing statistically significant non-occurring sequences which are unexpectedly absent in several genomes and proteomes. Read more about the evaluation method or follow the step-by-step user quide.

Genomic nullomers

Explore statistically significant absent sequences from various species


Peptide nullomers

Find out significant missing peptides in human and mouse proteomes


Nullomers in viruses

Browse statistically significant non-occuring motifs in viruses