Concentration Calculator
An Excel tool to calculate exactly how much stock solution to add.
In biosensor development, especially electrochemical platforms, calibration often means preparing a series of solutions with increasing analyte concentration. Traditionally, this can involve washing off one solution and replacing it with the next. But here’s the problem:
You risk disrupting the sensor surface.
You introduce variability through inconsistent drying, rinsing, or timing.
You lose the stabilising environment around your immobilised receptor.
A better alternative? Serial spiking.
Instead of removing the previous solution, you simply add small volumes of concentrated stock solution to your existing buffer. This keeps the surface microenvironment stable, reduces handling error, and better mimics real-world sensing conditions where analyte concentration gradually rises.
But there’s a catch:
You can’t use the simple C₁V₁ = C₂V₂ formula anymore.
You need to account for the analyte already in the solution — otherwise, you’ll overshoot your target concentration.
Instead simply use the tool I have created for you!
This simple to use Excel file:
Calculates the exact volume of stock solution to add
Carries forward the final volume and concentration for your next step
Builds a clean spiking table for calibration curve prep
Avoids over-dilution and wasted reagent
Just enter your starting conditions, drag the formulas down, and let the table do the rest.
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