💡 Quick Summary
Mutate DNA introduces random base substitutions into a DNA sequence. You can control the number of mutations per sequence and whether the first and last three bases are protected — useful for preserving start and stop codons. Mutated sequences can serve as negative controls or help evaluate the significance of sequence analysis results.
📋 How to Use
- Paste a raw DNA sequence or one or more FASTA sequences into the textarea. Input limit: 1,000,000,000 characters.
- Set the number of mutations to introduce into each sequence (default: 10). Multiple mutations may land on the same position.
- Choose whether the first three bases can or cannot be mutated (default: cannot — preserves the start codon).
- Choose whether the last three bases can or cannot be mutated (default: can).
- Click Run. Each input sequence is mutated independently and output as a FASTA record. Use Copy to copy the plain-text result.
🔬 Applications
- Generating negative-control sequences for sequence analysis benchmarks
- Evaluating how many random mutations are needed to disrupt a motif or binding site
- Producing synthetic mutant libraries for in silico analysis
- Testing the robustness of ORF finders, pattern search tools, or alignment algorithms against noisy sequences
⚠️ Common Mistakes & Warnings
Each mutation picks a position at random within the allowed range. Multiple mutations can affect the same position, so the actual number of changed bases may be less than the requested mutation count.
Numbers, spaces, and any non-IUPAC characters are removed from the input before processing. The mutation count applies to the cleaned sequence.
When "cannot" is selected, positions 1–3 (start) or the final 3 positions (end) are excluded from the random mutation range. This is useful for sequences where the ATG start codon or a stop codon must be preserved.
