Lactose and/or sucrose fermenter organisms show colonies with a dark center surrounded by a blue or pink color, while lactose and/or sucrose non fermenter organisms show colorless colonies.

• 能够进行乳糖及(或)蔗糖发酵的菌种；菌落的中央会呈现深色；而周围则为蓝色或粉红色;而无法进行发酵的菌种；菌落则呈现无色.