1:100 dilutions

For every 30 minutes, collect a fresh sample and repeat the procedure from the 1:100 dilution.

Do a Clean program after each measurement.

Start a 30-minute countdown to remind you to collect the next sample.

1

Prepare the sample for BactoBox® measurement

1. Use a serological pipette to transfer a sample from the shake flask to a vial.

2. Use a permanent marker to label the vial cap with the sampling time.

3. Start a 30-minute countdown to remind you to collect the next sample.

4. Vortex 30 seconds at max speed to disaggregate bacteria.

5. Make a 1:100 dilution:

   1. Transfer 101 µL of your sample to 10 mL of diluent.

   2. Vortex 10 seconds at max speed.

6. Transfer the tubing kit to the diluted sample.

2

Measure the diluted sample on BactoBox®

1. Click the Measure button in Access.

2. Add metadata:

   1. Dilution: 100.

   2. Label: E_coli_growth.

3

Clean the device

1. Transfer the tubing kit to the disinfection vial.

2. Click Clean.

Summary

The 1:100 dilution scheme works well for the measurements during lag and early-exponential growth stage. As the concentration increases, you'll need to dilute more. We will explain this in detail in the next section.