Free AI-Assisted

Oligo QC Instant

Paste or upload up to 100 primers for instant GC%, multi-method Tm, and traffic-light QC—no login, no upload.

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Key facts

Key facts about Oligo QC Instant
FactValue
InputsPlain text, FASTA, or CSV (name + sequence); pair mode with forward and reverse
Batch limitUp to 100 primers per run
Tm methodsWallace rule, SantaLucia 1998 NN, Owczarzy 2008 salt-corrected NN
Structure QCHairpin ΔG, self-dimer ΔG; pair mode adds heterodimer and 3′ overlap
Polymerase presetsQ5, Phusion, Taq, KAPA HiFi, Custom buffer
ExportCSV download and TSV copy to clipboard
Runs in browserYes — sequences not uploaded
Account requiredNo
HistoryLast 10 runs stored locally in browser

What it does

Validating a primer panel before ordering means bouncing between IDT, NEB, and spreadsheets—one oligo at a time, with no batch export and no plain-English warnings when hairpins or dimers look risky. Oligo QC Instant accepts plain text, FASTA, or CSV (up to 100 primers), runs entirely in your browser, and returns a sortable QC table with GC%, three Tm methods side by side, hairpin and self-dimer ΔG, and PASS / CAUTION / FAIL badges you can click for guidance.

Switch between Single / Batch and Primer pair mode. In pair mode, enter forward and reverse sequences to see ΔTm, heterodimer ΔG, 3′ overlap, and a recommended annealing temperature for your polymerase buffer preset (Q5, Phusion, Taq, KAPA, or Custom Na⁺/Mg²⁺/dNTP). Results auto-update for five or fewer sequences; click Analyze for larger batches. Export CSV or copy the table to a spreadsheet; reload the last 10 sessions from the History tab.

Why researchers use it

  • QC up to 100 primers in one paste or upload
  • See Wallace, NN, and salt-corrected Tm together
  • Get plain-English warnings for hairpins and dimers
  • Check primer pairs for ΔTm and heterodimer risk
  • Keep sequences private with client-side calculation
  • Export QC tables for lab notebooks or LIMS

Best for

  • Multiplex PCR primer panels before ordering
  • Core facility intake QC on submitted oligos
  • Graduate students validating primer lists from literature
  • Quick pair checks when NEB or IDT login is inconvenient
  • Spreadsheet-free batch GC% and Tm review at the bench

When to use this vs alternatives

Choose Oligo QC Instant for fast batch primer QC with exportable pass/fail flags and no account. Use the Primer Tm Calculator when you need co-solvent correction, larger batch pair limits, and detailed Ta rules per polymerase. IDT OligoAnalyzer remains the reference for deep single-oligo analysis when server-side BLAST and extinction coefficients are required.

What makes it different

IDT OligoAnalyzer is accurate but requires login, runs one oligo at a time, and sends sequences to IDT servers. NEB Tm Calculator matches polymerase buffers but lacks batch mode and secondary-structure QC. Legacy oligo calculators use Wallace rule only and skip dimer checks.

Oligo QC Instant combines no-login batch input, three Tm methods with tooltips, traffic-light severity badges with corrective suggestions, primer-pair mode with recommended Ta, and CSV export—without uploading sequences. Use the [Primer Tm Calculator](/tools/tm-annealing-temperature-calculator) when you need DMSO/formamide correction, up to 200 pairs, and detailed method comparison for annealing temperature planning.

How to get started

  1. Open the workspace on the Oligo QC tab.
  2. Choose Single / Batch or Primer pair mode.
  3. Paste sequences, FASTA, or CSV—or upload a file.
  4. Select polymerase buffer and primer concentration (default 250 nM).
  5. Click Analyze (auto-runs for ≤5 sequences in batch mode).
  6. Click badges for plain-English guidance; Export CSV or Copy table.

Frequently asked questions

Which Tm value should I use for PCR?
Use the salt-corrected NN Tm when your polymerase preset matches your PCR buffer (Na⁺, Mg²⁺, dNTP). Wallace rule is a quick estimate for short oligos; NN is more accurate for design. Compare all three columns and match buffer conditions to your enzyme manufacturer protocol.
What do PASS, CAUTION, and FAIL mean?
PASS means metrics are within default thresholds. CAUTION flags extreme GC%, short length, moderate hairpin stability, or ΔTm above 5°C in pair mode—review before ordering. FAIL indicates invalid characters, strong hairpins, stable dimers, or significant 3′ complementarity; redesign is recommended.
Are my sequences sent to a server?
No. All parsing, Tm, and structure calculations run in your browser. Sequences are not transmitted unless you explicitly use API mode with your own API key.

Client source code & registry

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