Effective inactivation of a wide range of viruses by pasteurization

Gröner, Albrecht; Broumis, Connie; Fang, Randel; Nowak, Thomas; Popp, Birgit; Schäfer, Wolfram; Roth, Nathan J.

Virus titrations were performed immediately when the test samples were generated. The virus titration was performed in a standard microplate assay. The samples to be assayed and controls, for example, positive assay controls, were serially diluted in cell culture medium. The infectivity titer 6 standard error of each sample was calculated according to the Spearman-K€ arber method. For lowering the detection limit (LOD), up to 10 mL of spiked and pasteurized, undiluted test sample was inoculated in cell culture flasks to test for infectious virus (large-volume testing). The 95% confidence limits of a titration were within 60.5 log. The virus RF was generally reported in one of two ways. Where no infectivity was detected in any of the replicate runs (infectivity level below the LOD as indicated by ""), the largest RF was selected as the demonstrated RF was limited only by the virus load in the spiked starting material and the LOD of the assay. Where at least one of the replicate runs resulted in residual infectivity, the mean of the RFs was calculated.