It is important to make sure only one cell occupies each droplet to be able to attribute each droplet’s behavior, such as fluorescence signal intensity, to a single cell behavior. On the other hand, it is preferred to avoid droplets without any cells to increase the efficiency of the experiment and reduce the reagent consumption.

However, this might be challenging to achieve since cells are randomly distributed in their carrier solution. It has been shown that cell encapsulation follows the Poisson formula in this case.

\[ P(X)=\frac{\lambda^{X}e^{-\lambda}}{X!} \]

In this formula, P shows the fraction of droplets that will contain X cells. \( \lambda \) is the mean number of cells per droplet and is calculated by multiplying cell concentration by the droplet volume. Input the cell concentration and droplet size in the calculator to find the average number of cells and fraction of droplets containing 0, 1, and 2 cells in your experiment.