Molecular probes designed to report the presence of target analytes—particularly those associated with human disease—via fluorescence transduction, are of great interest to the measurement science and biomedical communities. By taking advantage of the upregulated nature of a target biological analyte, it may be possible to offer highly selective detection and imaging of target presence within individual cells and in tissues. This presentation focuses on a novel group of light emission-silent probes from which is generated a fluorescent reporter due to probe activation by an intracellular oxidoreductase that is directly associated with a wide variety of cancers. To be discussed is the ability to detect individual cancer cells expressing high levels of the oxidoreductase, as well as imaging of 3-dimensional tumor mimics.Robin McCarley, Louisiana State University,