David Geffen School of Medicine 2 articles published in JoVE Bioengineering Time-Resolved In Vivo Measurement of Neuropeptide Dynamics by Capacitive Immunoprobe in Porcine Heart Nicholas Kluge1, Shyue-An Chan1, Jeffrey L. Ardell2,3, Corey Smith1 1Department of Physiology and Biophysics, Case Western Reserve University, 2University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, 3UCLA Neurocardiology Research Program of Excellence, UCLA Established immunochemical methods to measure peptide transmitters in vivo rely on microdialysis or bulk fluid draw to obtain the sample for offline analysis. However, these suffer from spatiotemporal limitations. The present protocol describes the fabrication and application of a capacitive immunoprobe biosensor that overcomes the limitations of the existing techniques. Genetics Determining Genome-wide Transcript Decay Rates in Proliferating and Quiescent Human Fibroblasts Mithun Mitra1,2, Ha Neul Lee1,2,3, Hilary A. Coller1,2,3 1Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, 2Department of Biological Chemistry, David Geffen School of Medicine, 3Molecular Biology Institute Interdepartmental Program, University of California, Los Angeles We describe a protocol for generating proliferating and quiescent primary human dermal fibroblasts, monitoring transcript decay rates, and identifying differentially decaying genes.