Publication Details (including relevant citation information):
Tanja A. Grein, Ronald Michalsky, M. Vega Lόpez, Peter Czermak: Purification of a recombinant baculovirus of AcMNPV by ion exchange membrane chromatography (submitted, Journal of Virological Methods).
Significant progress in the application of viral vectors for gene delivery into mammalian cells and the use of insect viruses as sustainable bio pesticides in agriculture require development of methods for virus purification and concentration. Ion exchange membrane chromatography is focused in this work as an efficient and economically attractive tool for virus downstream processing. Stability of the industrially employed baculovirus Autographa californica M nucleopolyhedrovirus was tested at ionic conductivities of the liquid phase ranging from 0.77-78.00 mS/cm and at H3O+ activities ranging from pH 3-8. Viral infectivity rapidly decreased by several orders of magnitude when ionic conductivities fell below 5 mS/cm (i.e., water flux from the surrounding liquid into the viral particle equivalent to an osmotic pressure change of about 0.49 MPa) or at H3O+ activities below pH 5.5 (rationalized with particle aggregation). The virus was concentrated and purified successfully via adsorption of viral particles to three different strong anion exchange membranes, in the range of (2.0 ± 1.0) x 109 to (1.1 ± 0.7) x 1010 pfu/ml membrane, and elution at pH 6.1 and 6.35 mS/cm. Virus recovery and concentration in accord with the reduction in liquid volume and concurrent reduction of host cell protein concentrations below the detection limits were obtained using a polyether sulfone-based membrane with quaternary ammonium ligand.