Limits of detection

BactoBox® counts individual particles. If there are too few particles, the concentration estimate is too uncertain. If there are too many particles, we can't tell them apart. Therefore, we have limits of detection (LoD). BactoBox® outputs concentrations in these ranges:

• 30 000–5 000 000 cells/mL

• 30 000–5 000 000 total/mL

The figure below shows how the LoD influences the BactoBox® output. The figure uses total/mL as an example but the very same thing is true for cells/mL.

Limits of detection (LoD) and how they influence the BactoBox® output.

Don't know the concentration of your sample?

Make a dilution series and measure the most diluted sample first. This avoids clogging your BactoBox® setup. It also avoids carry-over from your previous sample vial.

Once you are above the lower limit of detection (30 000 cells/mL), target a concentration of 0.5–4 million cells/mL.

Single cell at a time

The following figure shows how both too few and too many cells cause trouble.

BactoBox® uses an electric field to measure individual cells. Below the LoD (top), next-to-nothing enters the electric field and the cells/mL concentration is uncertain. Within the LoD (middle), individual cells enter the electric field so we can tell them apart and count them. Above the LoD (bottom), multiple cells enter the electric field at the same time and we can't tell them apart.