Cooley LLP View Institution's Website 1 article published in JoVE Bioengineering Multi-analyte Biochip (MAB) Based on All-solid-state Ion-selective Electrodes (ASSISE) for Physiological Research Wan W. Amani Wan Salim1, Michael A. Zeitchek1, Andrew C. Hermann1, Antonio J. Ricco2, Ming Tan2, Florian Selch2, Erich Fleming2, Brad M. Bebout2, Mamoun M. Bader3, Aeraj ul Haque4, D. Marshall Porterfield5 1Department of Agricultural and Biological Engineering, Birck-Bindley Physiological Sensing Facility, Purdue University, 2NASA Ames Research Center, 3Department of Chemistry, Pennsylvania State University Hazleton, 4Cooley LLP, 5NASA Life and Physical Sciences, Human Exploration and Operations Mission Directorate, NASA Headquarters All-solid-state ion-selective electrodes (ASSISEs) constructed from a conductive polymer (CP) transducer provide several months of functional lifetime in liquid media. Here, we describe the fabrication and calibration process of ASSISEs in a lab-on-a-chip format. The ASSISE is demonstrated to have maintained a near-Nernstian slope profile after prolonged storage in complex biological media.