Assessing changes in the expression levels of cell surface proteins with a turn-on fluorescent molecular probe

Tri-nitrilotriacetic acid (NTA)-based fluorescent probes were developed and used to image His-tagged-labelled outer membrane protein C (His-OmpC) in live Escherichia coli . One of these probes was designed to light up upon binding, which provided the means to assess changes in the His-OmpC expression levels by taking a simple fluorescence spectrum. A turn on fluorescent molecular probe was used to assess changes in the expression level of His-tagged cell surface proteins in living bacteria.