Single Cell Biology
Currently, the redox state of single, living cells is accessible only by fluorescence microscopy. Upon oxidation or reduction of key amino acids associated with fluorescent redox proteins, conformation changes cause differences in emission wavelength. Thus, the relative amounts of oxidized and reduced protein can be used to gauge the redox environment of a cell. Similarly, the redox state can be studied if the emitting protein is specific to a certain metabolite species, as has previously been shown (Cambronne et. al., 2016, Science) for cytosolic NAD+. Unfortunately, these experiments cannot be performed in the absence of light. It has been shown that the act of shining light on a cell can have a deleterious effect on metabolism. For instance, cytochrome C absorbs blue light and degrades, decreasing mitochondrial respiration with time. We are developing nanoelectrode probes to study how wavelength and intensity of light affects cell metabolism at the single cell level. Furthermore, we are fabricating metabolite-specific nanoelectrodes. This research can be used across a vast range of cell lines to study variations in metabolism across different areas of human disease.