In a Yeast Two-Hybrid Analysis of Several Strains Containing Different $\beta$

Multiple Choice

In a yeast two-hybrid analysis of several strains containing different prey/bait combinations, the screening of interacting proteins is done by growing cells on a medium containing X-Gal. White and blue colonies are observed after incubation. Which of the following statements is NOT true regarding blue/white selection in the yeast two-hybrid method?

A) Blue colonies result from X-Gal hydrolyzed by the reporter enzyme $\beta$ -galactosidase.
B) White colonies result from cells in which the prey and bait proteins do not interact.
C) Galactose released from X-Gal hydrolysis does not contribute to a colony's blue color.
D) White colonies indicate that $\beta$ -galactosidase catalyzed the hydrolysis of X-Gal.
E) Blue colonies are an indication that GAL4 activated transcription of GAL1-lacZ.