Biology & DNA Tools

Free browser-based tools for DNA sequence analysis, protein work, cell culture, and plasmid design. No account needed, nothing leaves your device.

DNA & Nucleic Acid Tools

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Reverse complement, GC content, primer Tm, PCR setup, gel planning and sequence analysis.

DNA Reverse Complement

Compute the reverse complement of a DNA sequence (A↔T, C↔G) instantly.

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GC Content Calculator

Calculate the GC content percentage and base composition of a DNA sequence.

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DNA Base Counter

Count the occurrence of each nucleotide (A, T, C, G) in a DNA sequence.

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DNA Sequence Cleaner

Clean a DNA sequence by removing whitespace, numbers, and non-standard characters.

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DNA to RNA Transcription

Transcribe a DNA sequence into RNA by replacing thymine with uracil (T→U).

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ORF Finder

Find open reading frames (ORFs) in a DNA sequence across all 6 reading frames, from start (ATG) to stop codon.

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Agarose Gel Calculator

Recommend agarose gel percentage by DNA size and calculate agarose powder and buffer volumes for gel preparation.

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GC Content Distribution

Plot GC percentage along a DNA sequence with a sliding window to spot GC-rich and AT-rich regions.

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Local Alignment + Dot Plot

Compare two DNA sequences with a dot plot and Smith-Waterman local alignment, showing score and identity.

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Restriction Analysis

Find restriction sites in a sequence and simulate single or double digests with fragment sizes.

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Restriction Enzyme Database

Search restriction enzymes by recognition site, overhang, buffer, methylation sensitivity and supplier.

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CRISPR gRNA Design

Find SpCas9 target sites with PAM, GC content and an on-target quality score.

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Codon Optimization

Reverse-translate a protein into DNA using host codon usage, or optimize an existing CDS.

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Synonymous Mutation Design

Add or remove restriction sites without changing the encoded protein sequence.

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Chromatogram Viewer (.ab1)

Open Sanger .ab1 trace files in your browser and read called bases with quality values.

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CDS Protein Editor

Edit the protein encoded by a CDS and get back a minimally changed DNA sequence, with every base change labelled.

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Primer Design & QC Tools

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Design primer pairs from a template, check hairpins and dimers, calculate oligo MW and OD yield, and set PCR conditions.

Primer Design Tool

Design PCR primer pairs from a template and a target region, with Tm, GC content and product size for each pair.

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Primer Tm Calculator

Calculate primer melting temperature (Tm) using the Wallace rule and salt-adjusted formula, with GC content and length.

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Primer Checker

Check a primer for hairpins and dimers, and scan a template for off-target binding sites with mismatch tolerance.

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Oligo Calculator

Calculate oligo molecular weight, GC content and extinction coefficient, plus the water volume that gives a 100 µM stock.

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PCR Calculator

PCR helper calculator — estimate annealing temperature, extension time, product mass, and amplification fold from cycle count.

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In-Silico PCR Tool

Predict every amplicon a primer pair can produce on your template.

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Overlap Extension PCR Tool

Fuse two fragments by SOE PCR and check the overlap before you order primers.

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Molecular Cloning

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Design seamless assemblies before you order primers: Gibson, Golden Gate, In-Fusion, Gateway, SLiCE, TA/TOPO and site-directed mutagenesis.

Gibson Assembly Calculator

Check homology arms and assemble multiple DNA fragments into one sequence.

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Golden Gate Assembly Tool

Check 4 nt overhang compatibility and assemble Type IIs parts in one pot.

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In-Fusion Cloning Calculator

Design 15 bp homology arms and assemble fragments by homologous recombination.

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Gateway Cloning Calculator

Locate attB sites on vector and insert and generate the expression clone.

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SLiCE Cloning Calculator

Plan Seamless Ligation Cloning Extract reactions with 25 bp homology arms.

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TA & TOPO Cloning Calculator

Simulate TA and TOPO cloning of a PCR product into a linear vector.

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Site-Directed Mutagenesis Tool

Design primers for point mutations, insertions and deletions in one step.

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Protein Tools

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Translation, molecular weight, isoelectric point, amino acid composition and enzyme kinetics.

DNA Translation Tool

Translate a DNA sequence into a protein using the standard genetic code, with all 6 reading frames and stop codon detection.

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Protein Molecular Weight Calculator

Calculate the molecular weight of a protein from its amino acid sequence (1-letter or 3-letter codes).

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Codon Table

Browse the standard genetic code table — all 64 DNA and RNA codons mapped to amino acids, with 1-letter and 3-letter codes.

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Protein pI Calculator

Calculate the isoelectric point (pI) of a protein from its amino acid sequence, with net charge at pH 7 and charged residue counts.

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Amino Acid Composition

Analyze the amino acid composition of a protein — count, percentage, and mass contribution of each residue.

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Protein Domains & Motifs

Predict transmembrane helices, hydropathy, signal peptides, coiled-coils and common motifs from an amino acid sequence.

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Enzyme Kinetics

Fit Michaelis-Menten kinetics with a Lineweaver-Burk plot — estimate Vmax and Km from substrate-rate data.

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Protein Structure Analyzer

Analyze a PDB, mmCIF or FASTA file: chains, sequences, secondary structure, molecular weight, pI and a hydrophobicity profile.

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Cell Culture

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Counting, plating, growth, media preparation and clonogenic assay calculators for routine culture work.

Cell Culture Calculator

Cell counting (hemocytometer), seeding volume, split ratio, and viability — common cell culture calculations.

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Cell Seeding Calculator

Calculate cell seeding density by culture vessel area — compute total cells, stock volume, and diluent volume for any plate or flask.

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Cell Doubling Time Calculator

Work out doubling time, number of doublings and specific growth rate from two cell counts, then project cell numbers over 24 to 120 hours.

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Cell Culture Media Recipe Calculator

Calculate how much FBS and how much of each supplement to add to a final medium volume, and how much basal medium is left over.

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CFU & Plating Efficiency Calculator

Calculate CFU/mL and plating efficiency from colony counts, and back-solve how many cells to seed for a target colony number.

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Assays & Quantification

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Calibration curves, activity units and quantification calculators for assay readouts.

Dose-Response Curve Fit (IC50)

Fit a 4-parameter logistic curve to dose-response data and solve IC50 or EC50.

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qPCR Standard Curve Calculator

Fit a qPCR standard curve from your Cq values and read off amplification efficiency, slope, R² and ΔCq — then back-calculate an unknown sample's template quantity.

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DNA Copy Number Calculator

Convert DNA mass to molecule copy number (and back) from template length, with a quick-reference table for amplicons, plasmids, E. coli and human genome templates.

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Protein Assay Calculator (BCA/Bradford)

Build a BCA or Bradford standard curve, interpolate sample absorbance to protein concentration, and correct for the dilution factor.

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Enzyme Activity Unit Converter

Convert between U, mU, nkat, µkat and katal, or compute activity from an absorbance rate using extinction coefficient, path length and protein concentration.

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Statistics Calculator (t-test & ANOVA)

Summarise data with mean, SD, SEM and 95% CI, or run Welch's t-test, a paired t-test and one-way ANOVA with exact p values.

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Nucleic Acid Quantification (A260/A280)

Convert A260, A280 and A230 readings into DNA or RNA concentration, total yield, purity ratios and pmol/µL.

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Plasmids

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Interactive plasmid designer with restriction sites, ORFs and sequence features.

Plasmid Designer

Upload a GenBank/FASTA plasmid, draw a circular map, annotate restriction sites, and export PNG/SVG.

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