Density Gradient Media – News and Views

Compared to CsCl and sucrose there are considerable procedural advantages to the use of OptiPrep for the purification of rAAV.

OptiPrep is a sterile solution of 60% (w/v) iodixanol; simply dilute it with saline to prepare sterile gradient solutions. It is the only gradient medium manufactured under strict FDA and EU cGMP compliance.

CsCl and sucrose are toxic to cells and must be removed prior to infection of cells. Iodixanol is non-toxic to cells; it has very low endotoxin levels; measured levels on each batch are <0.13 EU/ml. No dialysis is required before re-infection of cells. A Certificate of Analysis is available for each batch.

CsCl gradients lead to major reductions in infectivity of rAAV:  higher recovery of rAAV from iodixanol gradients compared to CsCl gradients and average particle number /infectivity ratios much lower in iodixanol isolates compared to CsCl isolates

CsCl must be removed prior to HPLC or gel electrophoresis; iodixanol rarely needs removing prior to further processing.

For more information on the purification of rAAV and an up-to-date reference list click here.

Written by JohnG
Filed under: Virus