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PCR, qPCR & Molecular Biology

DNA Fragment Molar Mixing Workbench

Convert entered dsDNA fragment lengths and mass concentrations to fmol/µL, then calculate volumes for declared relative molar parts anchored to the first fragment's entered volume.

Biology · experimental measurements

Support insert–vector, ligation and multi-fragment assembly arithmetic in one inspectable ledger without selecting a molar ratio, reaction amount or protocol.

Private calculations in your browser · explicit inputs and model boundaries
Example preview · Insert and vectorDeclared fragment molar amounts
Vector6.06060606 fmol
Insert18.1818182 fmol

Bars show the calculated fmol amounts that implement the entered relative parts; the first fragment's volume anchors the absolute scale.

  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example

Fragments: label, length bp, concentration ng/µL, target molar parts
1 row
Row 1

Empty rows are ignored until edited. Keep commas and tabs out of individual entries; use the paste view for comma- or tab-separated records.

Enter values in µL.

Calculation result

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Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

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Understand the relationship

The reasoning behind the result

Length converts mass concentration to molarity

c(fmol/µL) = c(ng/µL)×10⁶/(660L)

Longer dsDNA molecules contain more mass per molecule.

The displayed conversion uses the stated average 660 g/mol per base pair model.

Relative parts set amount ratios

ni/nanchor = partsi/partsanchor

The first fragment's volume fixes its fmol amount.

Every other volume follows from the entered part ratio and its own molar concentration.

A molar plan is not an assembly protocol

End chemistry, overlap design, purity, fragment count, topology and enzyme system affect experimental performance.

The workbench supplies no preferred ratio, mass ceiling or incubation condition.

Follow the numbers

Plan a 3:1 insert–vector mix

  1. Convert vector and insert ng/µL to fmol/µL from their lengths.
  2. Use the entered 1 µL vector volume to establish anchor fmol.
  3. Set insert fmol to three times the vector fmol.
  4. Divide target insert fmol by insert fmol/µL to obtain its volume.

The volumes implement only the declared molar parts under an average dsDNA mass model.

Quick guide

How to use this calculator

  1. Place the fragment whose volume is fixed in the first row.
  2. Enter measured mass concentrations and visitor-selected relative molar parts for every retained fragment.
  3. Check the calculated volumes against pipetting, total-DNA and protocol constraints outside this workbench.

Calculation method

Calculation and interpretation

Support insert–vector, ligation and multi-fragment assembly arithmetic in one inspectable ledger without selecting a molar ratio, reaction amount or protocol.

dsDNA fmol/µL = concentration(ng/µL)×10⁶/[660×length(bp)]; volumeᵢ = anchor amount×(partsᵢ/parts₁)/(fmol/µLᵢ).

Worked example

Plan a 3:1 insert–vector mix

The volumes implement only the declared molar parts under an average dsDNA mass model.

dsDNA fmol/µL = concentration(ng/µL)×10⁶/[660×length(bp)]; volumeᵢ = anchor amount×(partsᵢ/parts₁)/(fmol/µLᵢ).

Supported inputs

Precision and limits

Average dsDNA mass

Every fragment uses 660 g/mol per base pair; modifications, single-stranded regions and exact end chemistry are not modeled.

First row is the anchor

The first fragment's entered volume fixes the absolute amount; target parts are relative to its part value.

No ratio recommendation

Insert–vector, Gibson and other assembly ratios remain visitor-entered and protocol-specific.

No reaction validation

Purity, ends, overlaps, topology, inhibitors, enzymes, total mass and transformation remain external.

Continue calculating

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