Although reporter gene and fluorescent/luminescent probe based assays have been widely deployed in HTS with great successes, transfection of engineered cells and dye loading manipulation sometimes cause distortion in cell physiology, leading to loss of data fidelity and reliability22. The emergence of innovative label-free platforms aims at overcoming the limitations of label-based measurements by providing non-invasive means of detection. This approach enables real-time trace of kinetic information concerning a signal transduction process that is inevitably omitted by conventional traditional end-point assays. Current label-free systems used in cell-based investigations could be categorized into three major classes according to different detection principles: quartz microbalance, refraction index and cell impedance22, 23, 24 and 25. Quartz microbalance and refraction index are frequently employed in evaluation of binding properties of drug candidates, and are applicable to HTS. Impedance could be used in screening for potential leads that modulate a variety of biological events such as cell attachment, apoptosis, migration and activities of specific receptors such as GPCRs and tyrosine kinases. For example, CellKey system and RT-CES are amenable for 96- and 384-well plate based HTS with a throughput around 20,000 samples per 6 hours. However, significant cost associated with special assay plates makes these methods less attractive in large-scale operations.