How to use the glycerol stock preparation calculator
Find how much concentrated glycerol to add to a culture to reach a target glycerol percentage for freezing. Enter culture volume, target glycerol concentration, glycerol stock concentration in the fields above; the volume of glycerol stock to add is computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “glycerol stock volume”, “freeze bacteria in glycerol”, “glycerol percent calculation”, “calculate glycerol stock preparation”, “find volume of glycerol stock to add”.
Formula
Variables
- Vc — Culture volume (mL)
- f — Target glycerol concentration (%)
- s — Glycerol stock concentration (%)
Worked example
With culture volume = 10 mL, target glycerol concentration = 15 %, glycerol stock concentration = 80 %, the calculator gives volume of glycerol stock to add ≈ 2.307692 mL.
Tips for accurate results
- Enter the culture volume before adding glycerol; the formula gives the volume of stock to add to that culture.
- Freezing stocks are often prepared near 15% glycerol, but use the target your protocol specifies.
- Mix thoroughly after adding glycerol so the concentration is even before freezing.
Common mistakes
- Using the final volume as the culture volume, which gives a slightly low glycerol percentage.
- Entering the target as a fraction (0.15) instead of a percentage (15).
- Using glycerol that is less concentrated than the value entered for the stock.
Frequently asked questions
What is the glycerol stock preparation calculator used for?
Find how much concentrated glycerol to add to a culture to reach a target glycerol percentage for freezing. It helps with questions such as “glycerol stock volume”, “freeze bacteria in glycerol”, “glycerol percent calculation”.
What is the formula for the glycerol stock preparation calculation?
Volume of glycerol stock to add (mL) = Vc × f / (s-f). Here Vc is culture volume (mL), f is target glycerol concentration (%), s is glycerol stock concentration (%).
What inputs do I need for the glycerol stock preparation calculator?
You need culture volume in mL, target glycerol concentration in %, glycerol stock concentration in %. 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 glycerol stock preparation 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 glycerol stock preparation 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.