BIODE intends to t est the feasibility of a reusable electronic biosensor technology capable of detecting HIV antibodies directly in serum. This technology is based upon the merging of two relatively different technologies; Immunoassay and Acoustic Plate Mode (APM) micro sensors. The proposed biosensor technology will be capable of providing a semi- quantitative titer of the patient antibody to HIV. Biosensor assays for other infectious disease agents could likewise be developed. By combining the sensitivity of APM's with the specificity of immunoassays, BIODE is creating a novel sensor technology with the potential to overcome the drawbacks of existing techniques. This new serological biosensor will operate in a homogeneous mode and yet is expected to be as sensitive as existing techniques, such as ELISA and RIA. Thus, BIODE intends to demonstrate during this effort that the proposed biosensor will respond rapidly, in situ, with the target antibody, without enzyme amplification or radioactive isotopes. This is in contrast to current technology. The response will be an electronic signal, allowing numerous data handling options.