The qPCR Dilution Sample Capacity Estimator calculates how many complete qPCR reactions can be supplied from a prepared diluted sample. It combines the total diluted-sample volume, the amount used per reaction, and an optional volume kept aside as a handling reserve.
The result is intentionally based on whole reactions: any partial remainder that cannot supply another full reaction is not counted. This makes the estimate useful when assigning wells, checking whether a dilution will cover technical replicates, or deciding how much diluted template to prepare. The breakdown shows usable volume and leftover volume after the maximum whole-number reaction count is taken from the available sample.
It can also be used in reverse during planning: adjust the prepared volume or the reserve allowance until the displayed capacity covers the intended wells plus any additional repeats.
1. Enter prepared sample volume
Use the total volume of diluted template available for dispensing.
2. Enter sample per reaction
Specify the template volume added to each qPCR reaction or well.
3. Set a reserve volume
Optionally protect a small volume from being allocated; enter 0 if no reserve is needed.
4. Review whole-reaction capacity
The main result is rounded down to the largest number of full reactions that can be supplied.
Formula:
Usable volume = Prepared volume − Reserve volume Sample capacity = floor(Usable volume ÷ Sample per reaction)Leftover volume is the usable volume minus the volume consumed by the counted full reactions.
The result is the maximum number of complete qPCR reactions the prepared sample can supply under the entered dispensing plan.
The reserve is a planning allowance only; actual pipetting loss can vary with tube geometry, liquid handling equipment, and technique.
Given: 95 µL of diluted template is available, 3 µL is used per reaction, and 8 µL is reserved.
Calculation:
Usable volume = 95 − 8 = 87 µL.
Capacity = floor(87 ÷ 3) = 29 reactions.
Leftover = 87 − (29 × 3) = 0 µL.
Result: 29 complete reactions.
The 8 µL reserve remains untouched and is not included in the 29-reaction allocation.
A partial reaction cannot be counted as a complete usable well. The estimator therefore uses the floor of usable volume divided by the per-reaction volume.
It is volume intentionally not allocated to reactions to cover liquid that may be difficult to aspirate or that you want to keep as backup.
No, unless the field labeled sample per reaction actually represents the diluted sample portion you plan to dispense. This page is focused on sample capacity, not total reaction volume.
Yes if all three volume entries use the same unit. The displayed labels are microliters, so converting to microliters first avoids confusion.
Compare the complete-reaction capacity with the number of samples multiplied by the desired replicate count and any controls that also use this diluted sample.