The present invention provides improved compositions and methods for the collection of stem cells from an organ, e.g., placenta. The invention provides a stem cell collection composition comprising an apoptosis inhibitor and, optionally, an enzyme such as a protease or mucolytic enzyme, vasodilator, necrosis inhibitor, oxygen-carrying perfluorocarbon, or an organ preserving compound. The invention provides methods of using the stem cell collection composition to collect stem cells and to preserve populations of stem cells.