Measurements seem strange

Before you move on

You went through Qualification and your BactoBox® setup passed both phase A (QC vial) and phase B (dilution vial).

Is this not the case? Then let's take a step back. Did qualification fail? Does your BactoBox® not even power on?

See also BactoBox® acting up?.

My BactoBox® measurements seem strange

You are here because you measured your sample vial with BactoBox®, but the cells/mL or total/mL concentration doesn't align with your expectations.

You don't even get a cells/mL or total/mL concentration?

This means that you got an error message instead. See Error about conductivity, Error about slow/fast flow, or Error about electrical signal or noise.

Let's narrow it down. We know that your BactoBox® setup works since it passes qualification. In other words, it is your sample that we need to take a look at. See the following sections for details.

I expected better correlation with plate counts

You are here because you do BactoBox® measurements side-by-side with plate counts and the results don't align.

BactoBox® does correlate with plate counts but it requires that you prepare your sample first. Especially, that you break up clumps and chains.

Plate counts on bacterial clumps and chains

Bacterial aggregates are generally a pain to measure. If your bacteria form clumps or chains, neither BactoBox® nor plate counts give meaningful results.

We measure plate counts in colony-forming units (CFUs). However, a colony does not distinguish between single cells and aggregates. What does your CFU number mean then? Answer: "It depends". Not happy with that answer? Neither are we.

Always break up clumps and chains whether you measure with BactoBox® or perform plate counts.

Linearity and correlationBreak up clumps and chains

The cells/mL concentration is lower than expected

You may have to customize gating for your BactoBox®. This is an advanced topic. Reach out to us for help.

Gating

In general

Make sure that you prepare your sample so that it follows the requirements. See also our list of applications for protocols specific to specific use cases.

Prepare your sampleWhat can I measure on?Applications

Contact us

We are always happy to help if you require additional assistance.

Many questions can be answered using the powerful search function on this page, but you are also very welcome to contact us directly at: [email protected]