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Serial Dilution Sample Capacity Estimator

This estimator calculates how many complete serial-dilution series can be prepared from a limited stock sample and diluent supply. It compares the stock needed for the first transfer with the total diluent required across all steps, then uses whichever resource runs out first.

It is useful for bench planning before setting up repeated standards or sample dilution chains. The capacity is reported as a whole number of complete series, so partial leftover material is not counted as another usable series.

Calculator inputs

µL
µL
µL
µL
tubes
Result
—
Complete dilution series
Capacity from stock—
Capacity from diluent—
Diluent per series—

1. Enter available stock
Use the volume of original sample you are willing to allocate to these series.

2. Enter total diluent on hand
Use the same volume unit as all other volume inputs.

3. Define the first transfer
Enter the stock volume consumed to start one serial-dilution chain.

4. Describe each dilution tube
Enter diluent added per tube and the number of tubes in one complete chain.

5. Review the limiting capacity
The smaller of stock-based and diluent-based capacities determines the number of complete series.

Stock capacity = floor(Stock available ÷ Stock transfer); Diluent capacity = floor(Diluent available ÷ (Diluent per tube × Steps)); Complete series = min(Stock capacity, Diluent capacity)

The estimate assumes each complete series uses one initial stock transfer and the stated amount of diluent in every tube.

What the result means

The result is the maximum number of full serial-dilution chains supported by both stock and diluent under the entered setup.

Add a practical overage separately if your protocol requires dead-volume or pipetting-loss allowance.

Given: 1,250 µL stock, 12,000 µL diluent, 125 µL stock per series, 750 µL diluent per tube, and 4 tubes per series.

Calculation: Stock capacity = floor(1,250 ÷ 125) = 10. Diluent per series = 750 × 4 = 3,000 µL. Diluent capacity = floor(12,000 ÷ 3,000) = 4.

Result: You can prepare 4 complete series; diluent is the limiting resource.

Why does the result round down?

A partially supplied dilution chain is not counted as complete. The estimator therefore uses whole-series capacity only.

Do all volume fields need to be in µL?

The labels use µL, and all entered volumes should use that same unit. You can convert mL to µL before entering values.

Does transfer volume repeat at every dilution step?

This capacity model treats the stock transfer as the amount consumed to start each series. It separately counts diluent used in every tube.

Can I include a safety overage?

Yes. Reduce the available stock or diluent to the amount you actually plan to use, or increase per-series requirements to include your chosen overage.

What if I have plenty of one reagent?

The result is controlled by the more restrictive resource. The breakdown shows the independent capacity from stock and from diluent so the bottleneck is visible.