Figure 3.

Gel filtration of PNS containing fluorescent endosomes. As a first step in the purification of fluorescent endosomes, the PNS was applied to an S200 gel filtration column. The OD₂₈₀ is shown for the eluting fractions (0.8 ml each). The excluded volume eluted as a highly absorbing, light-scattering peak that contained the fluorescent endosomes. Fractions 7–11, indicated by the solid line, were pooled and loaded onto the bottom of a sucrose step gradient.