Determine concentration of inoculum

We want to inoculate using a well-defined seeding concentration of cells. For this you need to know the cell concentration of the liquid culture used to seed the growth medium. A 1:10 000 dilution is usually suitable for the BactoBox® measurement. See Hit the right concentration if the result is not within the working range.

Step by step

1

Retrieve a sample of the inoculum

Swirl the inoculum well to suspend cells and use a sterile serological pipette to collect 1 mL sample. Transfer to a sterile 5 mL centrifuge tube

2

Disaggregate cell clumps

Vortex the sample 1 min at max speed to disaggregate cell clumps.

3

Dilute 1:100

Transfer 101 µL of T0 culture to 10 mL of diluent. Vortex 10 sec. at max speed.

4

Dilute 1:10 000

Transfer 101 µL of the 1:100 dilution to 10 mL of diluent. Vortex 10 sec. at max speed.

5

Measure

Transfer tubing kit to the diluted sample. Press Measure and wait for the result to appear on the BactoBox® screen.

6

Calculate concentration

Multiply the cells/mL result with the dilution factor, in this case 10 000, to get the cell concentration of the inoculum

Summary

Once you know the cell concentration of the inoculum, proceed to Inoculate culture.