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DNA Sequence Toolkit

Free educational DNA calculator. Runs 100% in your browser — your sequence never leaves your device.

01 DNA Analysis Toolkit

Deterministic client-side calculation

DNA Sequence or FASTA block Cleaned length: 0 / 50,000 nt

Accepts plain sequence or FASTA. Headers starting with > are ignored. Max 50,000 letters.

Find motif:

2–20 letters, A C G T N only (optional)

Try preset:

DNA

Ready for calculation

Enter or paste a DNA sequence above or click an example preset, then click Calculate to view sequence properties, translations, and complements.

Length 0 nucleotides

GC Content 0.0% (G + C) / length

AT Content 0.0% 100 - GC%

Count A 0 Adenine

Count C 0 Cytosine

Count G 0 Guanine

Count T 0 Thymine

Count N 0 Any / Unknown

Melting Temperature (Tm):

Motif Search: No motif specified

Cleaned Sequence (5′ → 3′)

Reverse Complement (5′ → 3′)

Complement (No reversal, 3′ → 5′)

RNA Transcription (T → U)

Amino Acid Translation

Standard genetic code · Stop codons represented as * · Incomplete terminal codons ignored

Frame 1 Translation (Starts at position 1)

View all 3 reading frames simultaneously

Frame 1 (+1):

Frame 2 (+2):

Frame 3 (+3):

Export and summary tools:

Notice & Disclaimer

Educational use only. Not for clinical, diagnostic, therapeutic, or patient-care decisions. Do not paste patient or identifiable genomic data.

02 How It Works

Exact mathematical & biological formulas

1. GC Content & Base Composition

Every nucleotide letter in the cleaned sequence is tallied. The GC ratio is calculated deterministically as:

GC content (%) = (G + C) ÷ length × 100

AT content (%) is derived as 100 − GC %.

2. Complement & Reverse Complement

Using Watson–Crick base-pairing rules:

A ↔ T | C ↔ G | N → N

Complement: replaces each base with its complement without altering directionality.
Reverse complement: complements each base and reverses the sequence 5′ to 3′.

3. Transcription & Translation

Transcription: Replaces every Thymine (T) with Uracil (U).

Translation: Reads codons (triplets) in the chosen reading frame using the standard genetic code table:

Frame 1 begins at pos 1 · Frame 2 at pos 2 · Frame 3 at pos 3

Stop codons (TAA, TAG, TGA) are rendered as *. Incomplete terminal codons (1–2 trailing nucleotides) are ignored.

4. Melting Temperature (Wallace Rule)

The Wallace rule provides a quick heuristic estimate strictly for short oligonucleotides (≤ 14 nt):

Wallace Tm (°C) = 2 × (A + T) + 4 × (G + C)

Valid only for short oligos (≤ 14 nt) as a rough estimate — not for clinical primer design. For longer sequences, Tm is omitted.

All calculations are deterministic — the same input always gives the same output.

03 Frequently Asked Questions

Five common questions

Can I use this for diagnosis or treatment decisions?

No — educational use only. BioFluxAI is built strictly for learning, molecular biology education, and classroom exercises. It is not designed or validated for clinical, diagnostic, therapeutic, or patient-care decisions.

Does my sequence leave my browser?

No. Every calculation is performed locally in your browser memory using client-side JavaScript. There are no server uploads, no remote telemetry, no external database calls, and no accounts.

What does N mean?

In standard IUPAC nucleotide nomenclature, “N” represents an unspecified, unknown, or ambiguous base (any of A, C, G, or T). Our calculator counts N in the total length and translates unknown codons containing N into “?”.

Why is no Tm shown for my long sequence?

The Wallace rule applies only to short oligos (≤ 14 nt). For longer primers and double-stranded DNA constructs, thermodynamic nearest-neighbor models accounting for salt and divalent cation concentrations must be applied. Displaying a Wallace calculation for long sequences would be misleading.

Can I paste patient genomic data?

No — never paste identifiable or patient genomic data. This tool is built purely for textbook sequences, synthetic oligonucleotides, and educational problems.