Original instructional diagram for Molar Ratios in Ligation: Equal DNA Mass Does Not Mean Equal Molecule Count. Values, when shown, are illustrative; clinical images do not recommend a dose.
Compare molecules rather than equal masses
A shorter fragment has more molecules per nanogram than a longer fragment of the same strandedness. Matching insert and vector masses therefore does not generally give a one-to-one molecule ratio. Use both fragment lengths when translating a chosen ratio into masses.
Use Ligation Calculator to work through these inputs while keeping the displayed assumptions in view.
Treat the ratio as an input decision
An amount calculation does not choose the right ratio for every construct. Fragment quality, compatible ends and the validated method still matter. Keep the source of the chosen ratio with the calculation, rather than reading the result as a complete experimental procedure.
This question belongs to the Bio laboratory calculators group within Biology calculators.
Read the calculation on its stated basis
Insert mass = vector mass × insert length ÷ vector length × chosen insert-to-vector molar ratio.
Retain the input definitions and units with the result. A later comparison should use the same basis; a change in method is a new scenario, not simply a more precise version of the old number.
Keep related questions separate
DNA Copy Number Calculator addresses a related part of the measurement or interpretation task. Check its own method before carrying a value from one tool to the other.
For a related perspective, read DNA Mass to Molecule Copies: Check Fragment Length and Strandedness.
For tools in other subjects, return to GreenCalc. Keep the calculator result with its assumptions rather than using a link or a matching unit as evidence that two models are interchangeable.
By GreenCalc · Updated 2026-11-05