What is the reverse complement?

The reverse complement is the sequence of the antiparallel strand of a DNA double helix, read in the 5′ to 3′ direction. To obtain it, you first complement each base (A↔T, G↔C) and then reverse the resulting sequence. This is the strand that would be written on the other side of the helix.

How is GC content calculated?

GC content is the percentage of nucleotides in the sequence that are either guanine (G) or cytosine (C): (G + C) / total bases × 100. Higher GC content indicates a more thermally stable double strand because G-C base pairs are held together by three hydrogen bonds versus two for A-T pairs.

What is an open reading frame (ORF)?

An ORF is a continuous stretch of codons that begins with a start codon (ATG) and ends with a stop codon (TAA, TAG, or TGA). This tool locates the first ATG in the transcribed mRNA and translates codons until it hits a stop. Real genomes can have multiple overlapping ORFs; this tool reports the first one found.

Which characters are valid in the input?

Only the four standard DNA bases A, T, G, and C are recognised (case-insensitive). Spaces, dashes, digits, and IUPAC ambiguity codes (N, R, Y, etc.) are flagged as invalid and highlighted in the input. Remove them before running the analysis for accurate results.

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DNA Sequence Tools

Analyze DNA sequences: complement, GC content, transcription, and translation.

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关于此工具

DNA Sequence Tools is a comprehensive in-browser workbench for analysing nucleotide sequences. Paste any DNA sequence using the standard IUPAC bases A, T, G, and C. The tool immediately validates the input and highlights any invalid characters in red. Results are shown in clearly labelled panels: the complementary strand (3′→5′), the reverse complement (the actual antiparallel strand read 5′→3′), GC content percentage and AT content percentage, and a nucleotide frequency table. The Transcription panel converts the sense strand to the corresponding mRNA sequence (replacing T with U). The Translation panel finds the first open reading frame (ORF) starting at AUG and translates each codon to its standard single-letter amino acid code, stopping at the first stop codon. All computation is instant and runs entirely client-side.

使用方法

1 Paste or type your DNA sequence (A, T, G, C only) into the input box.
2 Invalid characters are highlighted red — correct them before proceeding.
3 Read the Complement and Reverse Complement in the first results panel.
4 Check GC and AT content percentages and the nucleotide frequency table.
5 Switch to the Transcription tab to see the corresponding mRNA sequence.
6 Switch to the Translation tab to see the first ORF translated to amino acids.

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