To discuss:
Several genetic systems use the β-galactosidase as a reporter. The lacZ gene encodes β-galactosidase. The major advantages and disadvantages of using the luciferase or green fluorescent protein as a reporter instead of the β-galactosidase.
Concept introduction:
The lacZ gene from E. coli encodes β-galactosidase enzyme, which is required for catabolism of lactose. The cells are plated on X-gal (5-bromo4-chloro-3-indolyl-b-D-galactopyranoside) containing media. Cells expressing β-galactosidase enzyme can be analyzed by their color of the colonies. X-gal, the chemical substance is cleaved by β-galactosidase enzyme and produces blue color colonies.
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Modified Mastering Microbiology with Pearson eText -- Standalone Access Card -- for Brock Biology of Microorganisms (15th Edition)
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