**1. Introduction**

Digital holographic (DH) microscopy is a digital high-resolution holographic imaging technique with the capacity of quantification of cellular status without any staining orlabeling of cells [1–3]. Various cellular parameters can be visualized and calculated from the particular hologram, including individual cell area, thickness, volume, and population confluence and cell counts [4–10]. One of the advantages of studying cells with DH microscopy is that they can be grown and analyzed in their normal growth medium during the entire study. The culture vessel will be placed on the microscope for imaging and then replaced in the 37°C incubator, or placed on a heating plate to retain 37°C, during the analysis. Since the first studies on living cells, DH microscopy has been used to study a wide range of different cell types, e.g., protozoa, bacteria, and plant cells, mammalian cells such as nerve cells, stem cells, various tumor cells, bacterial-cell interactions, red blood cells (RBC), and sperm cells [11–15].
