> For the complete documentation index, see [llms.txt](https://help.sbtinstruments.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.sbtinstruments.com/advanced/measurements-explained/gating.md). # Gating
BactoBox® counts and classifies individual particles in your sample vial. Gating creates two categories: *other* and *cells*. Together, *other* and *cells* give *total*. On the *Results* screen (see [Dash](/software/dash/user-interface.md)), you see *cells/mL* and *total/mL*. We do not show *other/mL* on the *Results* screen. You find *other/mL* in *summary.csv* (see [summary.csv](/software/file-formats/download-your-data.md)). {% hint style="info" %} ## Gating determines the category names The category names (e.g., *cells* and *total*) follow the gating. In some gating settings, the category names are *intact cells*, *custom cells*, and *total particles*. {% endhint %} ## Gating in flow cytometry BactoBox® is an impedance flow cytometer. All flow cytometers use [gating](https://en.wikipedia.org/wiki/Flow_cytometry#Gating) to classify (categorize) the individual objects in the sample. The *impedance* part means that BactoBox® uses electricity to probe each object. This happens in real time as several thousand objects in the sample pass through the [flow cell](/item-register/consumables/flow-cell.md). The electrical properties of a cell are unique. BactoBox® builds its gating around those properties. We call this gating BacTotal.

BactoBox® counts individual objects (bacteria and blue dots) in your sample vial. BactoBox® classifies some objects as cells (everything in the green rectangle) based on your applied gating. Conceptually, the gating is like the green rectangle in this diagram. Note that, like in real life, the gating is not perfect. A couple of the blue dots (particles) are inside the green rectangle (counted as cells). Likewise, a couple of bacteria are outside the green rectangle (counted as other).

## Gating settings in BactoBox® * [BacTotal](/advanced/measurements-explained/gating/bactotal.md) (recommended and the BactoBox® default) * [Legacy gating settings](/advanced/measurements-explained/gating/legacy-gating-settings.md) {% hint style="info" %} The gating setting used for each measurement is always displayed on the 'Results' screen and recorded in the *summary.csv* file for reference. {% endhint %} ### CRS file We store gating settings in a [CRS file](/software/file-formats/crs-file.md). For each of the rows in the table above, there is a corresponding CRS file. Use the [Gating](/software/access/pages/gating.md) page in [Access](/software/access/access.md) to see all CRS files on your BactoBox®. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.sbtinstruments.com/advanced/measurements-explained/gating.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.