Free AI-Assisted
Ligation Ratio Calculator
Calculate multi-ratio vector:insert pipetting volumes, picomoles, and water balance in one table—free, no account. Built-in AI agent assistant support.
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Key facts
| Fact | Value |
|---|---|
| Inputs | Vector size (50–500,000 bp), concentration (0.1–5,000 ng/µL), target mass (1–500 ng); insert size & concentration |
| Modes | Standard Ligation (1 insert) or Multi-Fragment Gibson/Golden Gate (up to 4 inserts) |
| Ratio columns | Selectable 1:1, 1:2, 1:3, 1:5, 1:7, 1:10, plus custom ratio |
| Cloning presets | Sticky End (1:1, 1:3), Blunt End (1:3, 1:5, 1:10), TA Cloning (1:3, 1:5), Gibson (1:1, 1:2) |
| Reaction volume | 5–50 µL total volume with configurable 10X buffer and enzyme volumes (default 1 µL each) |
| Outputs | Per-ratio vector & insert mass (ng), molar amount (pmol), volume (µL), and water balance (µL) |
| QC warnings | Sub-pipettable (<0.1 µL), negative water, volume overflow (>20%/50% DNA), small fragment (<50 bp) |
| Export options | Copy TSV table, CSV download (ligation_YYYY-MM-DD.csv), shareable URL hash |
| Runs in browser | Yes — 100% client-side; no server upload |
| Account required | No |
| AI assistant | Built-in; validates inputs, explains warnings, and interprets multi-ratio output |
What it does
Determining the optimal insert-to-vector ratio for T4 DNA ligation or multi-fragment assembly often causes failed transformants due to arithmetic errors or unpipettable microliter volumes. The Ligation Ratio Calculator automates vector-to-insert stoichiometry by taking plasmid lengths, stock concentrations, and target vector mass, then generating an instant multi-column pipetting table for all standard molar ratios in one view.
Instead of running separate calculations for 1:1, 1:3, 1:5, and 1:10 ratios in spreadsheet templates or single-output calculators, researchers select standard or multi-fragment mode and pick a cloning preset such as Sticky End, Blunt End, TA Cloning, or Gibson Assembly. The calculator uses double-stranded DNA molecular weight rules (660 g/mol/bp) to compute exact insert mass (ng), molar amount (pmol), and microliter pipetting volumes across every active ratio column simultaneously.
Each column functions as a complete reaction recipe breakdown. The calculator factors in user-defined buffer and ligase volumes, then computes the precise nuclease-free water volume required to hit the total reaction target (5–50 µL). If an insert volume falls below standard pipette accuracy (<0.1 µL) or if DNA volume exceeds reaction capacity, inline amber QC flags alert the user before pipetting begins.
Why researchers use it
- Compare 1:1 through 1:10 molar ratios simultaneously without re-entering stock concentrations
- Track picomoles alongside mass to verify reactions against NEB kinetic guidelines (0.02–0.03 pmol vector)
- Obtain complete component recipes including buffer, ligase, and nuclease-free water volume balance
- Plan multi-fragment Gibson and Golden Gate assemblies with up to four equimolar insert fragments
- Catch unpipettable volumes (<0.1 µL) and negative water balances before setting up bench reactions
- Share exact reaction parameters with lab mates using URL hash parameters or TSV clipboard export
Best for
- Sticky-end restriction fragment ligations testing 1:1 and 1:3 insert excess side-by-side
- Blunt-end plasmid ligations requiring 1:3, 1:5, and 1:10 molar ratios for optimal transformant yield
- TA cloning of PCR products into linearized vectors with 1:3 and 1:5 ratio columns
- Gibson Assembly and Golden Gate reactions combining up to four fragments in a 10 µL or 20 µL total volume
- Post-NanoDrop pipetting volume lookups when preparing parallel ligation reaction tubes
When to use this vs alternatives
Use the Ligation Ratio Calculator when you want a side-by-side ratio comparison table and complete reaction recipe for a single construct on one screen. For batch cloning projects requiring pooled master mixes across many distinct inserts, use the Ligation Insert Ratio Calculator. For fast single-ratio molecular weight and mass conversions without reaction recipes, use the Sequence Property Calculator.
What makes it different
Single-purpose web calculators compute only one ratio per calculation, forcing researchers to repeatedly re-enter concentration data when planning ratio sweeps. Generic spreadsheet templates lack automated volume rounding, picomole tracking, and inline warnings for sub-pipettable volumes or negative water balance.
Researchers switch to this calculator because it replaces fragmented calculation steps with a unified workspace. By presenting a complete reaction recipe alongside picomole metrics, it removes the need to maintain custom spreadsheet formulas or toggle between vendor tools during routine cloning.
How to get started
- Select your workflow mode: Standard (1 insert) or Multi-fragment (up to 4 inserts for Gibson or Golden Gate).
- Enter vector details: size in base pairs (bp or kb), stock concentration (ng/µL), and target vector mass (ng, e.g., 50 ng).
- Enter insert details: size (bp) and stock concentration (ng/µL). Click + Add Fragment if assembling multiple inserts.
- Pick a cloning preset chip (Sticky End, Blunt End, TA Cloning, or Gibson) or select custom ratio checkboxes.
- Set total reaction volume (µL), 10X buffer volume, and enzyme volume, then click Calculate.
- Review the multi-column output table, then click Copy All, CSV, or Share URL for your lab notebook.
Frequently asked questions
How is the required insert mass calculated for each ratio?
What is the recommended vector mass and picomole amount for T4 DNA ligation?
How does multi-fragment Gibson Assembly mode work?
What should I do if the calculator warns of negative water volume or sub-pipettable volumes?
Can I use ChatGPT, Cursor, or another AI agent with Ligation Ratio Calculator?
Client source code & registry
Last updated . Pepkio builds free lab calculators alongside bioinformatics CRO services.