The RNA Concentration Dilution Factor Estimator calculates the fold reduction needed to bring an RNA solution from its current concentration to a lower working concentration. For a chosen final volume, it also provides the volumes of RNA stock and diluent needed to make that preparation.
This is practical for normalizing RNA before reverse transcription, sequencing-library input, or side-by-side assay setup. The model uses a one-step ideal dilution and keeps the dilution factor separate from the actual mixing volumes. It does not account for recovery losses, degradation, or concentration changes caused by components that do not behave as simple additive volumes.
The calculated stock-volume fraction also provides a quick reasonableness check: multiplying the final volume by target concentration divided by starting concentration gives the same stock volume.
1. Enter current RNA concentration
Use the concentration measured for the undiluted RNA stock.
2. Enter the working target
Set the lower concentration needed for the next step.
3. Choose final preparation volume
Specify the total volume of normalized RNA you want to prepare.
4. Use the calculated mixing volumes
Combine the displayed stock and diluent volumes to reach the planned final volume.
Formula:
Dilution factor = Starting RNA concentration ÷ Target RNA concentration RNA stock volume = Final volume ÷ Dilution factor Diluent volume = Final volume − RNA stock volumeThe target must not exceed the starting concentration because the model only describes dilution.
The result is the fold dilution required to reach the selected RNA working concentration.
Large dilution factors may be easier to prepare as serial dilutions, particularly when the calculated stock aliquot becomes very small.
Given: RNA is 310 ng/µL, the desired working concentration is 25 ng/µL, and 124 µL is needed.
Calculation:
Dilution factor = 310 ÷ 25 = 12.4×.
RNA stock volume = 124 ÷ 12.4 = 10 µL.
Diluent volume = 124 − 10 = 114 µL.
Result: A 12.4× dilution using 10 µL RNA stock and 114 µL diluent.
Under ideal mixing, the 124 µL final solution is 25 ng/µL.
No. If the target concentration is above the starting value, removing solvent or another concentration method is needed rather than adding diluent.
Yes in this simple additive-volume model. If a protocol has non-additive volume behavior, follow that protocol instead.
Any matching concentration units can be used for the ratio. The page labels ng/µL, so convert other units first for clarity.
It means the final mixture volume is 12.4 times the RNA-stock aliquot volume. The remaining volume is diluent.
Serial dilution is useful when one-step stock volume is too small to measure reliably or when a protocol specifically calls for staged dilution.