Synthesis and Application of Photocaged Isopropyl β-D-1-Thiogalactopyranoside for Light-Mediated Control of Bacterial Gene Expression.

Photocaged compounds are chemical conjugates that are designed to release an active molecule upon exposure to light of a specific wavelength. In recent years, photocaged inducer molecules such as caged isopropyl β-D-1-thiogalactopyranoside (cIPTG) have been increasingly used as a powerful tool for light-driven gene expression in bacteria, allowing researchers to precisely and noninvasively tune the expression of specific target genes. In this chapter, we present a guideline for the synthesis of 6-nitropiperonyl photocaged IPTG (NP-cIPTG) as well as its in vivo application as an optochemical on-switch of gene transcription in Escherichia coli and other bacteria.