Human and equine influenza A virus in cell culture supernatant (serum-free and serum-containing cultivation) was directly adsorbed to Sartobind Q and D MA75 anion-exchangers. A light scattering detector was used to trace virus particles online. The intensity of scattered light was shown to correlate with viral HA activity. Dynamic capacities of Sartobind Q (operated at a flow rate of 264 cm h(-1)) were consistent but depended on the cell culture medium (3.12 kHAU cm(-2) for serum-free and 5.19kHAU cm(-2) for serum-containing medium). Elution of adsorbed virus from Sartobind Q by displacement with sodium chloride (up to 1.5 M, pH 7.0) resulted in average yields of 86% (based on HA activity). Elution from Sartobind D resulted in yields of only 38%. Lowering the pH (down to 4.2) or combining a low pH with salt displacement failed to elute virions. The pH of loaded supernatant was important with respect to recovery but not capacity. Preparative runs with Sartobind Q resulted in about five-fold enrichment of HA activity and 77% reduction in total protein. Host-cell DNA, in contrast, was recovered completely in the product fraction. The average virus yield was 72%. A productivity of 671 of culture broth m(-2) h(-1) was achieved. Due to their high productivity, ease of operation and acceptable yields Sartobind Q anion-exchangers can be considered promising candidates for the large-scale purification of cell culture derived influenza virus. (c) 2007 Elsevier B.V. All rights reserved.