Fig. 7

A factorial experiment testing the effect of copper, nickel, and zinc of virus inactivation in solution. Inactivation was tested using two different virus preparation procedures, unfiltered (red bars) and 0.2 µm filtered (blue bars). Combinations are as outlined in 1 and presented again below the figure. Each bar represents two technical replicates (n = 2), except in the case of center-points which had four technical replicates (n = 4). Asterisk indicates that at least one replicate was below the detection limit