How to use the antibiotic stock volume calculator
Find how much antibiotic stock to add to a medium to reach a working concentration. Enter stock concentration, working concentration, final medium volume in the fields above; the antibiotic volume to add are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “antibiotic stock dilution”, “ampicillin volume to add”, “working concentration antibiotic”, “calculate antibiotic stock volume”, “find antibiotic volume to add”.
Formula
Variables
- cs — Stock concentration (mg/mL)
- cw — Working concentration (µg/mL)
- Vf — Final medium volume (mL)
Worked example
With stock concentration = 100 mg/mL, working concentration = 50 µg/mL, final medium volume = 500 mL, the calculator gives antibiotic volume to add ≈ 250 µL; antibiotic volume to add ≈ 0.25 mL.
Frequently asked questions
What is the antibiotic stock volume calculator used for?
Find how much antibiotic stock to add to a medium to reach a working concentration. It helps with questions such as “antibiotic stock dilution”, “ampicillin volume to add”, “working concentration antibiotic”.
What is the formula for the antibiotic stock volume calculation?
Antibiotic volume to add (µL) = cw × Vf / cs. Antibiotic volume to add (mL) = [Antibiotic volume to add] / 1000. Here cs is stock concentration (mg/mL), cw is working concentration (µg/mL), Vf is final medium volume (mL).
What inputs do I need for the antibiotic stock volume calculator?
You need stock concentration in mg/mL, working concentration in µg/mL, final medium volume in mL. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the antibiotic stock volume calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the antibiotic stock volume result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.