Figure 1

Evaluation of 70% percoll for self-forming gradients. t = 0 hour: before centrifuge; t = 1, 2, 3 hour: 1, 2 or 3 hours after centrifugation at 27,000 g. A set of colored density marker beads from American density materials (Staunton, VA, USA) was used as density standards to determine the range of the buoyant density formed in the tubes. The density values of the beads are shown on the right side of the tubes.