Iodixanol: a nonionic iso-osmotic centrifugation medium for the formation of self-generated gradients

The physical and biological properties of Iodixanol, a new nonionic density gradient medium, are described in this paper. It is effectively a dimer of Nycodenz and it exhibits two significant advantages over previous iodinated density gradient media--its aqueous solutions are iso-osmotic up to a density of 1.32 g/ml and it is capable of forming self-generating gradients in 1 to 3 h. It has a very low toxicity toward biological material and enzyme assays can be carried out in its presence.