Free AI-Assisted

DNA RevComp & Primer Toolkit

Paste once for reverse, complement, and reverse-complement plus inline GC% and Tm—batch up to 100 primers, no upload. Built-in AI agent assistant support.

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Key facts

Key facts about DNA RevComp & Primer Toolkit
FactValue
InputsSingle sequence (dirty text or FASTA) or batch table / FASTA / CSV
OutputsReverse, complement, reverse-complement with per-field copy
QC metricsGC% (IUPAC-weighted), Wallace Tm, length, degenerate-base flags
IUPACFull degenerate complement map
Batch limitUp to 100 primers per run
Format optionsUppercase, FASTA header, wrap 60/80, DNA or RNA output
ExportCSV download and clipboard copy (batch)
Runs in browserYes — sequences not uploaded
Account requiredNo
HistoryLast 20 runs stored locally in browser

What it does

Getting a reverse complement is easy; getting revcomp plus GC%, Tm, and batch export in one step is not. Most web converters handle only the transformation, forcing you to paste results into separate QC tools. DNA RevComp & Primer Toolkit runs entirely in your browser: paste dirty sequence text (numbers and spaces stripped automatically), and see reverse, complement, and reverse-complement side by side with Wallace Tm, GC%, length, and primer-range warnings.

The RevComp tab auto-converts as you type. The Batch tab accepts name+sequence tables, FASTA, or one-sequence-per-line lists (up to 100 primers) and returns a downloadable CSV with all outputs and QC columns. Full IUPAC degenerate base complement mapping (R↔Y, K↔M, S/W unchanged, B↔V, D↔H) is built in. Output options include uppercase/lowercase, optional FASTA headers, line wrap at 60 or 80 characters, and DNA (T) or RNA (U) display. Reload the last 20 sessions from the History tab.

Why researchers use it

  • See reverse, complement, and revcomp in one view with per-output copy
  • Get GC%, Wallace Tm, and primer-length warnings without a second tool
  • Paste dirty GenBank or PDF text—digits and spaces are stripped visibly
  • Batch-convert primer lists from Excel with CSV download
  • Keep unpublished sequences local—no server upload in UI mode
  • Handle degenerate IUPAC primers with correct complement mapping

Best for

  • Quick reverse-primer design from a forward template
  • Batch revcomp of multiplex primer panels before ordering
  • Sanity-checking complement logic on degenerate primer codes
  • Bench-side conversion on tablet without switching apps
  • Exporting revcomp + QC tables for lab notebooks

When to use this vs alternatives

Choose DNA RevComp & Primer Toolkit for fast revcomp plus basic primer QC and batch CSV export without login. Use Oligo QC Instant for hairpin, dimer, and salt-corrected NN Tm. Vendor oligo analyzers remain the reference for extinction coefficient and BLAST when server-side analysis is acceptable.

What makes it different

reverse-complement.com and Bioinformatics.org SMS2 convert sequences but offer no GC%, Tm, or batch CSV export. IDT and Thermo Fisher tools add Tm but require login, process one sequence at a time, and upload data to vendor servers.

DNA RevComp & Primer Toolkit combines all-three-outputs view, inline Wallace Tm and GC% with primer-range flags, full IUPAC support, batch table workflow, and client-side privacy on one page. Use [Oligo QC Instant](/tools/oligo-qc-instant) when you need hairpin/dimer structure QC and salt-corrected NN Tm; use the [Primer Tm Calculator](/tools/tm-annealing-temperature-calculator) for polymerase-specific annealing temperature planning.

How to get started

  1. Open the RevComp tab (default) in your browser workspace.
  2. Paste a DNA sequence—or dirty text with numbers and spaces.
  3. Review reverse, complement, and reverse-complement outputs with QC badges.
  4. Toggle output options: uppercase, FASTA header, line wrap, DNA/RNA.
  5. Switch to Batch for primer lists; download CSV or copy the results table.
  6. Reload prior runs from the History tab.

Frequently asked questions

How is Tm calculated?
Tm uses the Wallace rule (2°C × AT + 4°C × GC) on a thermodynamically resolved sequence for ambiguous IUPAC bases. Wallace is appropriate for short primers; sequences longer than 25 nt are flagged to use nearest-neighbor methods for accuracy.
Does the tool handle degenerate IUPAC bases correctly?
Yes. Complement mapping follows standard IUPAC rules: R↔Y, K↔M, S and W unchanged, B↔V, D↔H, N↔N. Degenerate positions are flagged in QC output.
Are my sequences uploaded to a server?
No. All cleaning, conversion, and QC run locally in your browser. Sequences are not transmitted unless you explicitly use API mode with your own API key.

Client source code & registry

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Last updated . Pepkio builds free lab calculators alongside bioinformatics CRO services.