Cells are the main component of our structures and functions, but the effective methods to examine the viability and activity of cultured cells in a non-invasive and unlabeled measurement haven't been fully developed. In this study, we demonstrated a completely new cell measuring technique based on an attenuated total reflection (ATR) spectroscopy in terahertz (THz) region, which is emerging with promising biological science. The cultured cell showed lower absorption than the medium between 1 and 13THz, and the decrease of the cell viability indicates a good correlation to the ATR signal.
