Sequence Alignment Viewer
Allineamento globale di sequenze DNA o proteiche con algoritmo Needleman-Wunsch. Tool client-side: la tua sequenza non lascia il browser.
Sequenze in input
FASTA con header > o DNA/proteina grezzo (A-Z). Max 100 caratteri.
FASTA con header > o DNA/proteina grezzo (A-Z). Max 100 caratteri.
Risultato allineamento
| match. mismatch gap- inserzione/delezione
ACGTACGTACGTAAGCTAGCTAGC-
ACGTAGGTACGTAA-CTAGCTAGCT
Per studenti di Bioinformatica
L'algoritmo di Needleman-Wunsch (1970) è il fondamento dell'allineamento globale. Usa la programmazione dinamica per trovare l'allineamento ottimale tra due sequenze intere, minimizzando penalità per gap e mismatch.
Questo tool fa parte della sezione Università e supporta studenti delle magistrali in Bioinformatica di:
- UniBa - primo corso magistrale Bioinformatica del Sud Italia
- Tor Vergata - Bioinformatica con 1/3 percorso in laboratorio
Approfondisci la teoria con la serie UniAppunti / Bioinformatica.
Come utilizzare Sequence Alignment Viewer
Insert two sequences
Attach Sequence A and Sequence B in FASTA format (with header >) or as raw DNA/Protein, or click "Load example" for a pre-set case.
Set scoring parameters
Adjust match score, mismatch penalty and gap penalty to adapt the Needleman-Wunsch algorithm to your case.
Read alignment and statistics
Check score, ID%, gap% and number of matches/gaps; scroll multi-character lines with |(match), .(mismatch) and space(gap).
Deepen your knowledge with UniAppunti resources
Use links to University and Bioinformatics series to study the theory behind the Needleman-Wunsch algorithm.
Suggerimenti
- Use "Load Example" to see immediate alignment with match, mismatch and mixed gap scenarios.
- Increase absolute value of gap penalty to harshly penalize misalignments.
- Similar sequences with a more negative mismatch penalty highlights the precise differences between the two sequences.
Domande frequenti
What algorithm does the tool use to align sequences?
Needleman-Wunsch (1970), a dynamic programming algorithm of O(n*m) for global alignment, aligning two sequences from start to finish without cuts.
What is the maximum sequence length supported?
Characters left: 100. Text is truncated automatically to ensure browser performance, as dynamic programming matrices grow O(n*m).
What do the symbols | . and space mean in the central alignment line?
The symbol | indicates an exact match between the two bases or amino acids, a dot. indicates a mismatch (bases of different alignment), a space indicates a position of gap (insertion or deletion).
Are my sequences being sent to a server?
No, calculations are performed entirely in the browser using JavaScript client-side: the sequence never leaves your device.
How do scoring parameters affect alignment results?
A higher match score favors alignments with more exact matches; a less negative gap penalty makes it more convenient to insert gaps instead of forcing mismatches, changing the optimal alignment shape.