The ultimate goal is to develop small, inexpensive, disposable devices for rapid, on-site identification of biologically active molecules (hormones, metabolites, specific bacteria, etc.). The goal is based on the principle of mass loading onto a biosensitive material. An increase in mass on the surface of the biosensitive material will alter the output signal received by an automatic reader. The investigators will design a screening system with two biosensors which will reference one another. When a solution containing the test material is exposed to the sensors, they will experience mass loading of the specific material to different degrees. The degree of mass loading on the biosensors will be determined by an automatic reader. Phase I efforts will accomplish the following tasks: Task l) Design a bioscreening system that will operate under various conditions. Task 2) Develop techniques for binding bioactive materials. Task 3) Critically quantitate the binding dynamics on the surface of the material. This will require the use of radiolabeled materials so that the binding kinetics can be critically defined. Task 4) Evaluate sensitivity of the bioscreening system using a model reaction. This will require the development of algorithms to correlate the changes perceived by the automatic reader.