The DNA Concentration Sample Capacity Estimator calculates how many complete sample preparations can be made from an available DNA stock volume when each preparation consumes a fixed volume. An optional dead-volume allowance can be subtracted first so the estimate does not allocate every last microliter in the tube.
The page is useful for plate planning, replicate setup, and deciding whether a DNA stock must be re-extracted or diluted before a batch. Capacity is rounded down to a whole number of samples, and the breakdown reports both the usable stock volume and the residual volume that remains after the maximum count of complete samples has been allocated.
If different sample types consume different aliquot volumes, run each group separately rather than averaging the per-sample requirement, because whole-sample rounding can change the final capacity.
1. Enter available DNA volume
Use the stock volume currently available for the batch.
2. Enter volume required per sample
Specify the DNA aliquot consumed by one complete sample or reaction.
3. Set dead-volume allowance
Reserve volume that should not be counted as pipettable stock; enter 0 if none is needed.
4. Review capacity and remainder
The result counts only complete samples and shows the usable remainder after allocation.
Formula:
Usable volume = Available stock volume − Dead volume Sample capacity = floor(Usable volume ÷ DNA volume per sample)Unallocated usable volume = Usable volume − (Sample capacity × DNA volume per sample).
The result is the largest whole number of samples that can receive the required DNA aliquot from the usable stock.
This volume-based estimate does not check whether each aliquot also contains a required DNA mass; use concentration and mass requirements separately when that constraint matters.
Given: A DNA tube contains 68 µL, each sample needs 2.25 µL, and 4 µL is reserved as dead volume.
Calculation:
Usable volume = 68 − 4 = 64 µL.
Capacity = floor(64 ÷ 2.25) = floor(28.444...) = 28 samples.
Allocated volume = 28 × 2.25 = 63 µL.
Usable remainder = 64 − 63 = 1 µL.
Result: 28 complete samples.
The 4 µL dead-volume allowance is excluded from the usable 64 µL.
Not directly. This calculator is volume-based; if a minimum DNA mass is also required, first confirm that the per-sample volume at the measured concentration supplies enough DNA.
Some liquid may be intentionally left behind or may be difficult to recover reliably. Reserving it prevents the capacity estimate from assuming the entire tube is usable.
Yes. The per-sample field accepts decimals, but consider the practical precision limits of the pipette or dispenser you will use.
The remainder is less than one full per-sample aliquot, so it cannot support another complete sample under the entered plan.
You can reduce the volume consumed per sample when the protocol allows, increase available stock volume, or reduce the reserved dead volume if handling permits.