This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The resource has witnessed an increasing demand for applications targeting metabolism. To facilitate this we have developed several new technologies or integrated others to allow the study of cellular metabolism through several approaches. A number of these are reported on elsewhere. A key technique has been the application of self-referencing microsensors which to date have been constructed by hand (see SPID 0047) and with variable results. Although our efficiency here has greatly improved, manual production of amperometric sensors remains a bottleneck. To circumvent this we need to incorporate less variability in the construction, better define our optimal conditions and ultimately incorporate some form of automated or semi automated production. Overall we need to be in the position to supply microelectrodes meeting the exacting requirements of a non-invasive modulation technique for signal detection.