Cell invasion is the ability of malignant tumor cells to invade normal surrounding tissue, which contributes in large part to the significant morbidity and mortality of cancers. The CytoSelect™ Cell Invasion Assay Kit utilizes polycarbonate membrane inserts (8 µm pore size) to assay the invasive properties of cells. The kit contains twelve 8 um polycarbonate membrane inserts coated with an ECM gel layer in a 24-well plate. Cells must degrade the ECM layer and then move through the pores of the membrane. Invasive cells are then quantified using the provided fluorometric dye.