> 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/tutorials/measure-vitroid-tm-disc.md). # Do a simple measurement This tutorial is for your first bacterial measurement on BactoBox®. The tutorial is simple, fast, and predictable. You will learn how to prepare bacterial suspensions for BactoBox® measurements. For this tutorial, the success criterion is to get a BactoBox® measurement within 30,000 to 5,000,000 cells/mL. The below table lists the overall considerations for this tutorial. We use similar tables for our microbial process development [Workflows](/mpd/workflows/bioprocess-workflows.md) so you know if the workflow is right for you and what time to set aside. You can complete this tutorial as a :school\_satchel:Beginner to BactoBox® measurements.

BactoBox® skill level	Time to complete (E. coli)	Hands-on time	Requirements
🎒 Beginner	⏳ 0.5 hours	⏱️ 0.5 hours	7.6a ≥ v2026.02a Escherichia coli WDCM 00013 Vitroids™

## Soluble *E. coli* Vitroids™ disc For this tutorial you need to procure [*Escherichia coli* WDCM 00013 Vitroids™](https://www.sigmaaldrich.com/DK/en/product/sial/vt000137) ATCC^® 25922 from Sigma/Merck. Lead time is usually 1-5 days. Price is \~200 USD including shipping. 10 vials are included in each shipment. Concentration per disc is stated as 50,000-150,000 CFU mean value range. The discs are convenient for this tutorial as they dissolve easily in water and have a well-defined concentration of bacteria within the working range of BactoBox® measurements.

A soluble Vitroid™ disc containing 50,000–150,000 CFU of *E. coli* ATCC® 25922 .

## How to get a successful measurement on BactoBox® Three criteria are essential to get a reliable cell concentration on BactoBox®. Below is the checklist. The sample should ideally be a single-cell suspension, i.e. without cell clumps. Conductivity must be within 1,500–2,200 µS/cm. Concentration of the diluted sample must be between 30,000 - 5,000,000 objects/mL ### Disaggregation of cell clumps The most important learning of this tutorial is how to get a single-cell suspension. The below video explains why large clumps must be disaggregated before the individual cells can enter the measurement channel.

## Overview In this tutorial we will demonstrate how to solubilize the disc and get the bacteria ready for BactoBox® analyses. The overall steps in the tutorial are given below. 1. [Get things ready](/tutorials/measure-vitroid-tm-disc/get-things-ready.md) 2. [Transfer disc](/tutorials/measure-vitroid-tm-disc/transfer-vitroid-tm-disc.md) 3. [Prepare sample](/tutorials/measure-vitroid-tm-disc/disaggregate-bacteria.md) 4. [Dilute and measure](/tutorials/measure-vitroid-tm-disc/dilute-and-measure.md) 5. [Summary](/tutorials/measure-vitroid-tm-disc/summary.md) ## Summary After this introduction you can proceed to [Get things ready](/tutorials/measure-vitroid-tm-disc/get-things-ready.md). --- # 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/tutorials/measure-vitroid-tm-disc.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.