How It Works
This calculator works in 4 steps.
Choose the series design
Select "dilute stock into tube 1" or "neat top tube".
Enter the factor and diluent volume
Type the step factor and diluent per tube.
Enter replicates and overage
Type the number of series and the overage percent.
Read the stock requirement
The calculator returns stock per series and total stock with overage.
The Formula
The formula sets stock use equal to one transfer volume, or one transfer plus the retained top volume, times the number of series.
V_stock = V_t × r × (1 + overage)V_stock = (V_t + V_d) × r × (1 + overage)V_t = V_d / (F − 1)- V_stock:
- Total stock consumed
- V_t:
- Transfer volume
- V_d:
- Diluent per tube
- r:
- Number of replicate series
A twofold series with 100 µL per well and a neat top well needs 200 µL stock per series. Three replicate series with 10% overage need 660 µL.
Conversion Table
The conversion table gives stock volume per series for 6 designs with a neat top tube, plus 10% overage.
| Stock | Factor | Diluent per tube | Stock (diluted first) | Stock (neat top) | Neat top + 10% |
|---|---|---|---|---|---|
| 1 mg/mL | 2 | 100 µL | 100 µL | 200 µL | 220 µL |
| 10⁹ CFU/mL | 10 | 900 µL | 100 µL | 1,000 µL | 1,100 µL |
| 100 µM | 5 | 200 µL | 50 µL | 250 µL | 275 µL |
| 10 mM | 3 | 150 µL | 75 µL | 225 µL | 247.5 µL |
| 1 µg/mL | 10 | 180 µL | 20 µL | 200 µL | 220 µL |
| 50 ng/mL | 4 | 300 µL | 100 µL | 400 µL | 440 µL |
What Is the Serial Dilution Stock Requirement Calculator?
The Serial Dilution Stock Requirement Calculator is a tool that returns the volume of starting stock a serial dilution consumes, for designs that dilute the stock into tube 1 and for designs that keep a neat top tube. The first design uses one transfer volume of stock; the second uses the transfer volume plus the volume kept as the top standard.
Stock requirement controls cost for antibodies, enzymes, and reference standards. The calculator adds an overage for pipette tip retention and lets the user enter replicate series, so the stock order covers the full plate.
Common Uses
There are 5 main uses of this calculator.
Reagent ordering
Lab managers order enough antibody or enzyme for a planned study.
Reference standard budgeting
Analysts track certified reference material use per run.
Scarce sample planning
Researchers fit a series within a small patient sample volume.
Aliquot sizing
Users freeze stock aliquots matched to one series.
Cost estimates
Grant writers price reagent cost per experiment.