PlasmidLab / Free tools / Reverse complement

Reverse complement a DNA sequence

Paste DNA to get the reverse complement, the reverse and the complement. IUPAC codes are complemented as well, and lower case stays lower case. It all runs in your browser, so the sequence is not sent anywhere.

DNA sequence

Skip FASTA header lines Remove spaces and numbers

Reverse complement

Reverse

Complement

What each output is

The complement swaps each base for its pair: A and T, C and G. IUPAC codes swap the same way (R and Y, K and M, B and V, D and H), and S, W and N stay as they are. U is complemented to A. The reverse reads the sequence backwards. The reverse complement is the other strand read 5′ to 3′, which is how a reverse primer is written.

Letters that are not DNA or IUPAC codes are kept in place and listed above the results, so a stray character is easy to spot.