Estimate the concentration of a qPCR dilution from the starting concentration, the aliquot transferred, and the final mixed volume. The result uses the standard conservation-of-solute relationship and also reports the effective dilution factor and the amount of diluent added. It is useful for checking a prepared standard or planning a one-step dilution before assembling a qPCR plate.
Final concentration = Stock concentration × Stock volume ÷ Final volume
Dilution factor = Final volume ÷ Stock volume. Diluent volume = Final volume − Stock volume.
The main result is the expected concentration after the stock aliquot has been brought to the entered final volume.
This is a volumetric estimate. Pipetting error, adsorption, degradation, and incomplete mixing are not modeled.
Starting with 100 ng/µL, transfer 2 µL and bring it to 20 µL. The concentration is 100 × 2 ÷ 20 = 10 ng/µL, the dilution is 10×, and 18 µL of diluent is required.
No. Use the same volume unit throughout so the volume ratio remains valid.
Adding diluent cannot raise concentration; concentration requires a different process.
Yes. Serial steps can make tiny stock transfers more practical and reproducible.
No. It calculates nominal volumes; add a justified preparation allowance separately if needed.
Prepare an intermediate dilution or increase the final volume instead of relying on an unreliable transfer.
| Variable | Meaning |
|---|---|
| C₁ | Stock concentration |
| V₁ | Stock aliquot volume |
| V₂ | Final mixed volume |
| C₂ | Calculated final concentration |