APTANEXUS / Source: https://www.aptanexus.com/ Credit: Anal Chem. 2026. doi: 10.1021/acs.analchem.6c02444.

Aptamer neighbour explorer

Follow a sequence to its closest neighbours, recorded targets, and shared motifs.

source records
unique searchable sequences
local structures
annotated / ambiguous records

Find a neighbourhood

Computed in your browser

6–500 bases. Whitespace is ignored; U and T are equivalent for similarity.

Try a sequence:

Loading the local snapshot and building the search index…
Browse the full collection · includes annotated and ambiguous sequences

RecordSequence IDTargetYearSearch eligibility
How to read these results
Sequence similarity, not a binding prediction
Targets come from the source records. Sequence resemblance and target frequency do not establish binding or affinity for your query.
Exact edit-distance
1 − Levenshtein distance / the longer sequence length. Insertions, deletions, and substitutions each cost one. Scores range from 0 to 1.
k-mer cosine
Frequencies of all 1–4-mers (340 features), standardized using the unique searchable sequences in this snapshot, then compared by cosine similarity. Scores range from −1 to 1. This captures composition and is not percent sequence identity.
Sequence handling
Case and whitespace are normalized, and U is mapped to T for scoring and grouping. Other symbols, ambiguous bases, and modification annotations are excluded from scoring and retained in the full collection browser. Exact-match hiding compares normalized sequences, including when using k-mer cosine.
Records and filters
Duplicate normalized sequences share one neighbour. Filters select source records before ranking; details retain their provenance. Alphabet filters describe letters present in the sequence, not confirmed DNA/RNA chemistry. Target types and level codes are displayed as supplied, without inferred labels.
Affinity and structures
Affinity text, pKd, MFE, and dot-bracket structures are shown as supplied. Structure diagrams are the downloaded source images; this viewer does not predict new structures. Source annotations have not been independently validated.