> 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-growth-curve.md). # Track growth curve This tutorial will teach you how to track a bacterial growth curve using BactoBox® as a stand-alone device. You should plan for approximately 4 hours of hands-on work and a total duration of 12 hours to complete the full growth curve experiment. During the first 5 hours, most of the time will be spent waiting for the culture to reach a suitable concentration. The first step is straightforward. To make your workday more efficient and avoid a long day in the lab, consider asking a colleague who arrives early to inoculate the culture before you begin. {% hint style="success" %} ## Complete tutorial and first Before starting this tutorial, first complete the [Do a simple measurement](/tutorials/measure-vitroid-tm-disc.md) and [Measure a dense culture](/tutorials/measure-overnight-culture.md). They are simpler and faster. The present tutorial is slightly more complex. {% endhint %} The goal of this tutorial is to generate a high-quality BactoBox® growth curve that enables reliable determination of the growth rate. This tutorial is suitable for :school\_satchel:Beginners and can be completed without prior experience using BactoBox® for growth measurements.

BactoBox® skill level	Time to complete (E. coli)	Hands-on time	Requirements
🎒 Beginner	⏳ 12 hours	⏱️ 4 hours	7.6a ≥ v2026.02a Escherichia coli WDCM 00013 Vitroids™

## *E. coli* Vitroids™ disc We recommend [*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.

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

{% hint style="info" icon="snowflakes" %} ## Alternative: Use an in-house *E.coli* glycerol stock instead of a Vitroids™ disc For the best experience, we recommend using [*Escherichia coli* WDCM 00013 Vitroids^™](https://www.sigmaaldrich.com/DK/en/product/sial/vt000137) from Sigma/Merck. Alternatively, you can prepare an overnight culture from an in-house *E. coli* glycerol stock. For detailed preparation instructions, see [Inoculate LB medium](/tutorials/measure-vitroid-tm-growth-curve/inoculate-lb-medium.md). {% endhint %} ## Hit the right conductivity The conductivity must be within the range of 1,500–2,200 µS/cm to be measured with BactoBox®. A 1:100 dilution is typically sufficient to achieve the required conductivity. For most growth media, undiluted cultures and 1:10 dilutions have a conductivity that exceeds the acceptable range. If such samples are measured, BactoBox® will display a conductivity error.

Conductivity measurements for a dilution series of the growth medium. Dilutions of 1:100, 1:1,000, 1:10,000, and 1:100,000 all fall within the accepted conductivity range of 1,500–2,200 µS/cm. In contrast, the undiluted growth medium and the 1:10 dilution exceed the acceptable conductivity range.

{% hint style="success" icon="square-bolt" %} ## Dilute at least 1:100 to hit the right conductivity. Most growth media must be diluted at least 1:100 to reach the conductivity range required for BactoBox® measurements (1,500–2,200 µS/cm). {% endhint %} ## Pre-incubate culture 5 hours before measurements The culture must be incubated before its cell concentration can be measured using BactoBox®. Once dissolved in 50 mL of growth medium, the Vitroids™ disc yields a cell concentration of approximately 1,000 CFU/mL. Based on experience, the culture typically requires around 5 hours of incubation before the cell concentration becomes detectable with a 1:100 dilution. ## Change dilution factors as the concentration increases Begin the measurements using a 1:100 dilution. As the cell concentration increases, use higher dilution factors, such as 1:1,000 and 1:10,000. The following subpages will guide you through each step. ## Overview The overall steps in the tutorial are given below. 1. [Get things ready](/tutorials/measure-vitroid-tm-growth-curve/get-things-ready.md) 2. [Inoculate LB medium](/tutorials/measure-vitroid-tm-growth-curve/inoculate-lb-medium.md) 3. [Prepare sample](/tutorials/measure-vitroid-tm-growth-curve/disaggregate-bacteria.md) 4. [1:100 dilutions](/tutorials/measure-vitroid-tm-growth-curve/1-100-dilutions.md) 5. [1:1,000 dilutions](/tutorials/measure-vitroid-tm-growth-curve/1-1-000-dilutions.md) 6. [1:10,000 dilutions](/tutorials/measure-vitroid-tm-growth-curve/1-10-000-dilutions.md) 7. [Data analysis](/tutorials/measure-vitroid-tm-growth-curve/data-analysis.md) 8. [Summary](/tutorials/measure-vitroid-tm-growth-curve/summary.md) ## Summary After this introduction you can proceed to [Get things ready](/tutorials/measure-vitroid-tm-growth-curve/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-growth-curve.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.