Abstract: A method for removal of host cell DNA from a sample containing a species of desired protein, virus, or extracellular vesicle comprising the steps of: Loading a substrate bearing an anionic metal affinity ligand with a metal ion, Equilibrating the substrate with a buffer having a pH in the range of pH 6 to pH 10, and a salt concentration in a concentration range up to 1 M which salt is not forming a chemical complex with the anionic metal affinity ligand, Contacting the sample with the metal-loaded anionic metal affinity substrate, Separating the substrate from the sample, wherein the sample has reduced content of contaminating DNA.

Abstract: A method for separating full Adeno-associated virus (AAV) capsids from empty AAV capsids in a buffered mixture comprising full AAV capsids, empty AAV capsids, comprising the steps of contacting the buffered mixture with a first substrate bearing a metal affinity ligand attached to the first substrate, said metal affinity ligand having the ability to complex metal ions via three or more nitrogen atoms, separating empty AAV capsids from full AAV capsids by eluting with a pH gradient, a salt gradient, a metal ion gradient or a combination thereof in the presence of multivalent cations bound to the metal affinity ligand to obtain a purified full AAV capsid fraction.

Abstract: A method for reducing a contaminating DNA content of a preparation containing AAV capsids and contaminating DNA, comprising the steps of a) Performing an extraction of DNA with a solid phase bearing positive charges at its surface said solid phase is contacted with the preparation at a pH of 7.0±1.0, and a salt concentration of 10 mM to 200 mM yielding a first fraction, (b) Diafiltering the first fraction by a first tangential flow filtration to obtain a second fraction, (c) Treating the second fraction with DNase, (d) Diafiltering the DNase treated second fraction obtained by step c) by a second tangential flow, (e) filtration to a buffer with pH of 7.0±1.0, and a salt concentration of 10 mM to 20 mM to yield a third fraction, and optionally (f) Concentrating the third fraction by tangential flow filtration before supplemental chromatography.