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.
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.
Open tool →GC Content Calculator
Calculate the GC content percentage and base composition of a DNA sequence.
Open tool →DNA Base Counter
Count the occurrence of each nucleotide (A, T, C, G) in a DNA sequence.
Open tool →DNA Sequence Cleaner
Clean a DNA sequence by removing whitespace, numbers, and non-standard characters.
Open tool →DNA to RNA Transcription
Transcribe a DNA sequence into RNA by replacing thymine with uracil (T→U).
Open tool →ORF Finder
Find open reading frames (ORFs) in a DNA sequence across all 6 reading frames, from start (ATG) to stop codon.
Open tool →Agarose Gel Calculator
Recommend agarose gel percentage by DNA size and calculate agarose powder and buffer volumes for gel preparation.
Open tool →GC Content Distribution
Plot GC percentage along a DNA sequence with a sliding window to spot GC-rich and AT-rich regions.
Open tool →Local Alignment + Dot Plot
Compare two DNA sequences with a dot plot and Smith-Waterman local alignment, showing score and identity.
Open tool →Restriction Analysis
Find restriction sites in a sequence and simulate single or double digests with fragment sizes.
Open tool →Restriction Enzyme Database
Search restriction enzymes by recognition site, overhang, buffer, methylation sensitivity and supplier.
Open tool →CRISPR gRNA Design
Find SpCas9 target sites with PAM, GC content and an on-target quality score.
Open tool →Codon Optimization
Reverse-translate a protein into DNA using host codon usage, or optimize an existing CDS.
Open tool →Synonymous Mutation Design
Add or remove restriction sites without changing the encoded protein sequence.
Open tool →Chromatogram Viewer (.ab1)
Open Sanger .ab1 trace files in your browser and read called bases with quality values.
Open tool →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.
Open tool →Primer Tm Calculator
Calculate primer melting temperature (Tm) using the Wallace rule and salt-adjusted formula, with GC content and length.
Open tool →Primer Checker
Check a primer for hairpins and dimers, and scan a template for off-target binding sites with mismatch tolerance.
Open tool →Oligo Calculator
Calculate oligo molecular weight, GC content and extinction coefficient, plus the water volume that gives a 100 µM stock.
Open tool →PCR Calculator
PCR helper calculator — estimate annealing temperature, extension time, product mass, and amplification fold from cycle count.
Open tool →In-Silico PCR Tool
Predict every amplicon a primer pair can produce on your template.
Open tool →Overlap Extension PCR Tool
Fuse two fragments by SOE PCR and check the overlap before you order primers.
Open tool →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.
Open tool →Golden Gate Assembly Tool
Check 4 nt overhang compatibility and assemble Type IIs parts in one pot.
Open tool →In-Fusion Cloning Calculator
Design 15 bp homology arms and assemble fragments by homologous recombination.
Open tool →Gateway Cloning Calculator
Locate attB sites on vector and insert and generate the expression clone.
Open tool →SLiCE Cloning Calculator
Plan Seamless Ligation Cloning Extract reactions with 25 bp homology arms.
Open tool →TA & TOPO Cloning Calculator
Simulate TA and TOPO cloning of a PCR product into a linear vector.
Open tool →Site-Directed Mutagenesis Tool
Design primers for point mutations, insertions and deletions in one step.
Open tool →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.
Open tool →Protein Molecular Weight Calculator
Calculate the molecular weight of a protein from its amino acid sequence (1-letter or 3-letter codes).
Open tool →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.
Open tool →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.
Open tool →Amino Acid Composition
Analyze the amino acid composition of a protein — count, percentage, and mass contribution of each residue.
Open tool →Protein Domains & Motifs
Predict transmembrane helices, hydropathy, signal peptides, coiled-coils and common motifs from an amino acid sequence.
Open tool →Enzyme Kinetics
Fit Michaelis-Menten kinetics with a Lineweaver-Burk plot — estimate Vmax and Km from substrate-rate data.
Open tool →Protein Structure Analyzer
Analyze a PDB, mmCIF or FASTA file: chains, sequences, secondary structure, molecular weight, pI and a hydrophobicity profile.
Open tool →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.
Open tool →Cell Seeding Calculator
Calculate cell seeding density by culture vessel area — compute total cells, stock volume, and diluent volume for any plate or flask.
Open tool →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.
Open tool →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.
Open tool →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.
Open tool →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.
Open tool →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.
Open tool →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.
Open tool →Protein Assay Calculator (BCA/Bradford)
Build a BCA or Bradford standard curve, interpolate sample absorbance to protein concentration, and correct for the dilution factor.
Open tool →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.
Open tool →Interactive plasmid designer with restriction sites, ORFs and sequence features.