DNA Sequence Reverse Complement Calculator

DNA Sequence Reverse Complement Calculator. In molecular biology, the reverse complement of a DNA strand is the sequence you'd find on the opposite strand running in the 5'→3' direction — essential for primer design, cloning, and sequence analysis. Enter your DNA sequence (using A, T, G, C) and select an operation type — Reverse Complement, Reverse Only, or Complement Only — to get the transformed result sequence. Secondary outputs include the original and result lengths in base pairs and the GC content of your sequence. Also try the use the Plasmid Copy Number Calculator.

Results

Result Sequence

Original Length

Result Length

GC Content

What is a reverse complement of a DNA sequence?

A reverse complement is created by first reversing the DNA sequence (reading it backwards) and then replacing each nucleotide with its complement (A↔T, G↔C). This is important for analyzing both strands of double-stranded DNA. See also our Transformation Efficiency Calculator.

When would I need the reverse complement of a DNA sequence?

Reverse complements are essential when analyzing open reading frames (ORFs) on the reverse strand, designing PCR primers, analyzing palindromic sequences, or working with antisense DNA strands.

What's the difference between reverse, complement, and reverse complement?

Reverse reads the sequence backwards, complement changes each base to its pair (A↔T, G↔C), and reverse complement does both operations - first reverse then complement the sequence.

What nucleotide codes are accepted by this calculator?

The calculator accepts standard DNA nucleotide codes: A (Adenine), T (Thymine), G (Guanine), and C (Cytosine). Other characters will be ignored or may cause errors.

How do I find ORFs on the reverse strand?

To find ORFs on the reverse strand, use the reverse complement option to get the sequence as it would appear on the opposite strand, then search for start codons (ATG) and stop codons in the resulting sequence.

What is GC content and why is it important?

GC content is the percentage of guanine (G) and cytosine (C) bases in the DNA sequence. It affects DNA melting temperature, primer design, and can indicate functional regions in genomic sequences.

Can I use this tool for RNA sequences?

This tool is designed for DNA sequences. For RNA sequences, you would need to replace uracil (U) with thymine (T) first, or use a specialized RNA tool that handles U↔A base pairing.

Is there a limit to the sequence length I can input?

While there's no strict limit, very long sequences may take longer to process. The tool works best with sequences up to several thousand base pairs for optimal performance. You might also find our DNA/RNA Molecular Weight Calculator useful.