Some early work on lacI generated various small molecule analogs similar in structure to IPTG in an effort to find more compounds which modulate the activity of lacI. ONPF was found to stabilize lacI when bound to DNA. Recent papers primarily used ONPF in structural determinations of the DNA bound form of lacI.
Based on these early experiments, I decided to test whether ONPF could act as an anti-inducer in our flow measurements. The fluorescence levels of lacI containing cells with plasmid-based Plac.YFP in the presence and absence of 1mM ONPF were compared using Flow Cytometry. However, no difference in fluorescence was observed.