Matrigel inhibits formation of endocrine and acinar cells in colonies supported by aECM-lam. Dissociated 7-day-old pancreatic cells were plated in the presence of designated doses of Matrigel and aECM-lam. (A) Photomicrographs of representative colonies over the course of 7 days. (B) Diameters of 7-day-old colonies (n=50) were increased by addition of Matrigel into aECM-lam containing culture. Individual points represent the diameter of each colony. Horizontal lines represent mean±SD. (C) Colony-forming efficiency in each condition was determined by dividing the number of colonies by the number of cells plated. Data represent the mean percentage±SD from triplicate wells. Addition of Matrigel at 1% enhanced, and at 5% inhibited, colony formation of postnatal progenitor cells when cultured in the presence of aECM-lam. (D) Conventional qRT-PCR analysis on total cells collected from 7-day-old cultures. Addition of Matrigel decreased expression of markers for endocrine and acinar cells, but increased ductal marker expression in colonies supported by aECM-lam. Data represent expression relative to β-actin. Mat, Matrigel; Lam, aECM-lam.