Reverse Complement Calculator
Compute reverse, complement, or reverse-complement for DNA/RNA sequences with FASTA support.
Reverse, Complement, and Reverse Complement Tool
DNA/RNA Sequence Manipulation Guide
Use reverse, complement, and reverse complement operations for primer design, strand checks, sequence alignment, and ORF finding.
- Reverse: Reverses the order of the input sequence.
- Complement: Generates the complementary DNA or RNA strand by replacing each base with its partner.
- Reverse Complement: Reverses the sequence first, then generates the complement. This is useful for checking features on the opposite strand.
Important Considerations
- Supported Formats: Raw DNA/RNA and FASTA input are supported. FASTA headers are preserved.
- Large Datasets: You can convert many sequences and download the result as a text file.
- Ambiguity Codes: IUPAC ambiguity codes are supported, including R/Y, K/M, B/V, and D/H pairs.
- Case Preservation: Uppercase and lowercase letters are preserved in the output.
- Client-Side Processing: Calculations run in your browser; sequences are not uploaded.
Nucleotide Ambiguity Codes
Ambiguity codes represent positions where the exact nucleotide may not be known. The table shows how each code is complemented.
| Code | Nucleotides | Complement |
|---|---|---|
| A | A | T |
| G | G | C |
| C | C | G |
| T | T | A |
| U | U | A |
| R | A or G (purine) | Y |
| Y | C or T (pyrimidine) | R |
| S | C or G (strong) | S |
| W | A or T (weak) | W |
| K | G or T (keto) | M |
| M | A or C (amino) | K |
| B | C, G, or T (not A) | V |
| V | A, C, or G (not T) | B |
| D | A, G, or T (not C) | H |
| H | A, C, or T (not G) | D |
| - | gap | unchanged |
| any other | any or unknown | unchanged |
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How to Use
- Paste or type your DNA/RNA sequence (raw text or FASTA).
- Select the operation you need: reverse, complement, or reverse complement.
- Copy or export the result for downstream analysis (primers, strand checks, annotations).
FAQ
What is the reverse complement used for?
It is commonly used to analyze features on the opposite strand, design primers, and work with strand-specific annotations.
Does it support ambiguity codes?
Yes. IUPAC ambiguity codes are supported (e.g., R↔Y, K↔M, B↔V, D↔H), and case is preserved.