Figure 1: Isolation, culture, and characterization of adult spinal disc stem cells from human spinal disc tissue. A. Photomicrograph taken with light microscopy at 20X magnification, of the first plating of adult spinal disc cells as a single cell suspension, at ultra-low densities, in suspension culture (10,000 cells per ml). B. Photomicrograph taken with light microscopy at 20X magnification of monoclonally derived sphere-like cellular clusters (discospheres), comprised of stem cells and early progenitors. Shown are spheres at day 10 of growth in suspension culture.