In iodixanol, peroxisomes are the densest organelle in the light mitochondrial fraction and are therefore easily separated from the other components (lysosomes, mitochondria, etc.) in a self-generated gradient. Self-generated gradients make sample handling very easy and are highly reproducible but need to be formed in either a vertical, near-vertical, or small volume high-performance fixed-angle rotor. The resolution of the peroxisomes is far superior than that in sucrose and, unlike in PercollⓇ there is no contamination from endoplasmic reticulum.