A cutting-edge collection of detailed, step-by-step techniques and protocols for constructing, evaluating, and using enzyme- and microbial-based biosensors. Ideal for novices starting research in their field or experienced researchers wanting to use a biosensor for a specific analytical measurement, the methods detailed here allow biochemists, analytical chemists, microbiologists, and engineers to successfully apply biosensor technology to their specific problems. The techniques include classical enzyme biosensors based on potentiometric, amperometric, conductimetric, optical, and thermal transducers, as well cell-based biosensors based on amperometric and optical transducers. A companion volume, Affinity Biosensors: Protocols and Techniques, by Rogers & Mulchandani, concentrates on cell- and affinity-based biosensors.