Biology
Ligation Insert Amount Calculator
Calculate how much insert DNA to mix with your vector for a chosen insert:vector molar ratio.
Your inputs
Change any value to update the result instantly.
Insert DNA needed
50 ng
Vector DNA
50 ng
Insert:vector molar ratio
3 : 1
Total DNA in reaction
100 ng
Molar ratios between 1:1 and 3:1 suit most ligations; higher ratios help short inserts. Keep total DNA within your ligase kit's recommended range.
What this calculator does
Calculates the mass of insert DNA needed for a chosen insert:vector molar ratio in a ligation reaction.
What your result means
The headline is the insert mass in nanograms to combine with the entered vector mass.
Formula and working
insert (ng) = vector (ng) × insert (bp) ÷ vector (bp) × molar ratio
- 1
Collect the inputs
Vector DNA amount = 50 ng; Vector length = 3,000 bp; Insert length = 1,000 bp; Insert:vector molar ratio = 3
- 2
Apply the formula
insert (ng) = vector (ng) × insert (bp) ÷ vector (bp) × molar ratio
- 3
Result
Insert DNA needed = 50 ng
Frequently asked questions
Symbols and assumptions
- ng
- Mass in nanograms
- bp
- Length in base pairs
- ratio
- Insert-to-vector molar ratio
- • Lengths are in base pairs for double-stranded DNA.
- • The molar ratio refers to insert molecules per vector molecule.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Optimal ratio varies with insert size and cloning method; follow your ligase kit's recommended total DNA range.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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