Growth of Capan-2 spheroids. The Capan-2 spheroids were grown in the presence of 10% serum (gray squares) or defined medium added with EGF and B27 (black triangles) without any medium change (a and b). (a) Spheroid size. The diameter of each spheroid was measured by microscopic observation with an ocular micrometer and sphere volume was calculated. (b) Cell viability. Spheroid viability was quantified by ATP monitoring with the luminescent ATPlite assay. (c) Induction of a quiescent state on Capan-2 spheroid. Capan-2 spheroid culture was initiated in presence of 10% serum and EGF and four days after culture initiation, EGF was (gray squares) or not (black triangles) removed from the culture medium. Capan-2 spheroid viability was followed during a 6 days additional period with the luminescent ATPlite assay. Each point is the mean ± SD of 6 spheroids.