> 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/mpd/workflows/cross-check/retrieve-culture-sample.md).

# Retrieve culture sample

Use your standard protocol for the cultivation. Let is run until EoF[^1] where you expect the culture to be in stationary stage and ready to be harvested.

{% hint style="success" icon="temperature-arrow-down" %}

## Stop further cell divisions by quick cooling

Arrest further growth by transferring the sample to an cold rack.

We want precise measurements with small error bars for each measurement method. If the cells are still dividing post-sampling, this will lead to drift in concentrations and pronounced variability.
{% endhint %}

## Step by step

{% stepper %}
{% step %}

### Retrieve a sample

Use a syringe or serological pipette to sample 5 mL culture to a 5 or 15 mL centrifuge vial. Cap lid tightly. Note down the sampling time.
{% endstep %}

{% step %}

### Disaggregate cell clumps

Vortex the vial 1 minute at maximum speed to disaggregate cell clumps. See [Break up clumps and chains](https://help.sbtinstruments.com/custom/advanced-sample-preparation/break-up-clumps-and-chains) if your bacterium needs more aggressive disaggregation than this.
{% endstep %}

{% step %}

### Arrest growth

Transfer the vial to a cold rack to arrest further growth.
{% endstep %}
{% endstepper %}

## Summary

You have now retrieved a culture sample at end-of-fermentation and arrested cell divisions. Next step is [BactoBox measurements](/mpd/workflows/cross-check/bactobox-measurements.md).<br>

[^1]: End-of-Fermentation


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