The RNA Concentration Reagent Volume Calculator calculates the RNA stock volume required to provide a selected RNA mass per reaction for a specified batch size. It is suited to workflows such as reverse transcription setup, library preparation, or assay normalization when the RNA concentration is already known.
The calculation links a mass requirement directly to the measured stock concentration, then scales the per-reaction aliquot by the number of reactions. This makes it easy to see whether the needed aliquot is comfortably pipettable and how much RNA stock the whole batch will consume. The tool reports exact theoretical volume and does not include an automatic excess for transfer loss or failed pipetting.
When several RNA samples have different measured concentrations, calculate each sample separately so every reaction receives the intended mass without forcing a single aliquot volume across unequal stocks.
1. Enter RNA concentration
Use the concentration of the stock that will be added to the reactions.
2. Set RNA mass per reaction
Enter the mass required for one reaction or preparation.
3. Enter the batch size
Provide the number of complete reactions being prepared.
4. Check total stock requirement
The result scales the per-reaction RNA aliquot across the entire batch.
Formula:
RNA volume per reaction (µL) = Target RNA mass (ng) ÷ RNA concentration (ng/µL) Total RNA volume = RNA volume per reaction × Number of reactionsThe total RNA mass equals target mass per reaction multiplied by the reaction count.
The main result is the total volume of RNA stock required to supply the requested RNA mass across the full batch.
If the calculated per-reaction aliquot is too small to pipette reliably, prepare a suitable working dilution and recalculate using its concentration.
Given: RNA concentration is 125 ng/µL, each reverse-transcription reaction needs 500 ng, and 14 reactions are planned.
Calculation:
RNA volume per reaction = 500 ÷ 125 = 4 µL.
Total RNA volume = 4 × 14 = 56 µL.
Total RNA mass = 500 × 14 = 7,000 ng.
Result: 56 µL of RNA stock is required.
Each reaction receives 4 µL of the 125 ng/µL stock to deliver 500 ng RNA.
Yes after keeping mass and concentration units compatible. Convert the target mass and concentration to a matching mass unit before using the calculation.
No. It gives the theoretical amount for the entered reaction count. Add your own overage according to the workflow if needed.
Use the mass you intend to deliver per reaction. You can run the calculator at the low and high ends to see the corresponding volume range.
No. Concentration and volume do not describe integrity or purity; those require appropriate quality measurements.
A working dilution can turn an impractically tiny calculated aliquot into a larger, more accurately pipettable volume.