ChemoFx® is a tissue-culture based test that, for an individual patient, measures a tumor's response to different chemotherapeutic agents in vitro. The ChemoFx response correlates with progression free interval in ovarian cancer. Oncologists can use this information to help select between clincally equivalent therapeutic options for individual patients. Cells may be obtained from biopsies, from a planned surgical procedure, or aspirated from ascites or pleural effusions.

ChemoFx is based on the adherent properties of malignant epithelial cells derived from carcinomas. In culture, these epithelial cells attach and spread to form cell monolayers. When these same epithelial cells are killed by chemotherapeutic drugs in vitro they undergo cell death by apoptosis and subsequently detach from the substratum. The counting of live cells remaining attached after drug treatment is a quantitative measure of cell kill.