Abstract
The ability to assess cell proliferation and viability is essential for assessing new drug treatments, particularly in cancer drug discovery. This study describes a new method that uses a plate reader digital microscopy cell imaging and analysis system to assess cell proliferation and viability. This imaging system utilizes high throughput fluorescence microscopy with two fluorescent probes: cell membrane-impermeable SYTOX green and nuclear binding Hoechst-33342. Here we compare this technology to other known viability assays, namely: propidium iodide (PI)-based flow cytometry, and sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) based plate reader assays. These methods were assessed based on their effectiveness in detecting the cell numbers of two adherent cell lines and one suspension cell line. Automated cell imaging was most accurate at measuring cell number in both adherent and suspension cell lines. The PI-based flow cytometry method was more difficult to use with adherent cells, while the SRB and MTT assays had difficulties when monitoring cells in suspension. Despite these challenges, it was possible to obtain similar results when quantifying the effect of cytotoxic compounds. This study demonstrates that the digital microscopy automated cell imaging system is an effective method for assessing cell proliferation and the cytotoxic effect of compounds on both adherent and suspension cell lines.