ISOLATION OF A RETROVIRUS FROM MULTIPLE-SCLEROSIS PATIENTS IN SELF-GENERATED IODIXANOL GRADIENTS

The use of Iodixanol, a relatively new iodinated gradient medium, is d escribed for isolation of a retrovirus, which was harvested from the s upernatant of lymphoid cell lines originating from patients with multi ple sclerosis (MS). The virus is produced in low amounts and has been shown to be fragile, as manifested in a loss of surface glycoproteins when purified in other gradient media. The gradient fractions were ana lysed after centrifugation in Iodixanol by incorporation of H-3-UTP, r everse transcriptase (RT) assays and electron microscopy (EM) and it w as found that Iodixanol does not cause the degree of damage to the par ticles observed previously. These more favourable conditions are proba bly due to low viscosity and almost iso-osmotic conditions even in hig h concentrations. Furthermore, these advantages go together with highe r reproducibility in self-forming gradients, easier handling and short er centrifugation time. Iodixanol can also be used for preparation of HTLV-1. (C) 1998 Elsevier Science B.V. All rights reserved.