DNA Sequence Complement

A fast, robust tool for generating complementary, reverse, and reverse-complement DNA sequences. It ignores whitespace and numbers, strictly processing A, T, C, G, and U.

JavaScript Required: This interactive tool requires JavaScript. Manually: swap A with T (or U for RNA), and C with G.

Input Sequence (5' to 3' recommended)

Why Reverse Complement?

Because DNA is antiparallel. If the coding strand is 5'-ATGC-3', the template strand is 3'-TACG-5'. When reading sequences from databases (which conventionally present 5' to 3'), finding a binding site on the opposite strand requires searching for the reverse complement (5'-CGTA-3').