Answer to Question #81610 in Genetics for susan Guido

Question

If a wildtype bacterium is grown in the presence of the sugar X-gal, transcription of the polycistronic m-RNA does not occur. What is X-gal unable to do? Without adding lactose (or genetically modifying the bacteria), how could you fix this problem

Answer 1

X-gal is unable to induce transcription of genes under lac operon. It means that it does not bind repressor. In order to fix this proglem, IPTG (Isopropyl β-D-1-thiogalactopyranoside) is added to the medium.