The cell viability of OVCA ex vivo tumor cultures was determined in accordance with a protocol previously described by our group.28 (link) Briefly, cell viability was verified at days 3 and 6 or 7 by incubating 2–3 hours 50 μL of CellTiter 96 AQueous One Solution Proliferation Assay reagent (Promega, Wisconsin, USA). Absorbance was read at 492 nm using a Fluostar OPTIMA analyzer (BMG Labtech, Offenburg, Germany). Each time data point was normalized to the vehicle control group.