Materials: 

- Ethanol

- 37% hydrochloric acid

- Centrifuge

- Tubes

Procedure:

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

- Remove culture media, weigh the remaining pellet, add the same amount of ethanol and vortex for 5 minutes. Separate supernatant and pellet and acetify each with about 300µl of 37% hydrochloric acid till the color turns to red. 

- 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.