Materials: 

- 37% hydrochloric acid
- Centrifuge
- Tubes

Procedure:

Spin down the bacterial solution at 4500g for 10 minutes.

Remove culture media, weigh the remaining pellet and acetify with the same amount of 37% hydrochloric acid. 

Spin down the resolved pellet at 13,3g for 10 minutes and Remove supernatant.

The anthocyanidin is present in the organic and the aqueous phase; the color can be changed by adjusting the pH-value.