Cell Viability Assay with 3D Prostate Tumor Spheroids

WST-8 (Cell Counting Kit 8; CCK-8) is the last generation tetrazolium-based cell viability assay and has recently been accepted as a validated method for measuring the cell viability of 3D in vitro models. Here, we describe how to form 3D prostate tumor spheroids using the polyHEMA technique, apply drug treatments and WST-8 assay to these spheroids, and calculate their cell viability. The advantages of our protocol are the formation of spheroids without adding extracellular matrix components, and the elimination of the critique handling process needed for transferring spheroids. Although this protocol exemplifies the determination of percentage cell viability in PC-3 prostate tumor spheroids, it can be adapted and optimized for other prostate cell lines and other types of cancers.