Cytotoxicity assays are routinely used in many laboratories for a variety of purposes from assessing the health of cell cultures to evaluating the toxicity of a panel of compounds. The measurement tool employed for these assays needs to be reliable, easy to use, and relatively fast. The Countstar Rigel system (Fig 1) is a smart, intuitive cell analysis instrument that streamlines a wide variety of cellular assays including transfection, apoptosis, cell surface marker, cell viability, and cell cycle assessments. The system provides robust fluorescence quantitative results. The easy-to-use, automated procedure guide you to complete a cellular assay form imaging and data acquisition.