Fig. 1.

Selection of thermally resistant virus. (a) Schematic representation of the experimental process used to select thermally resistant EVA71. (b) To determine a suitable incubation temperature for thermal stressing while retaining the ability to recover infectious virus, a series of temperatures were used. Virus stocks at 10⁶ p.f.u. ml⁻¹ were incubated at the indicated temperature (x-axis) for 30 min and samples were titred by plaque assay, n=1. (c) To generate a virus population resistant to incubation at the selected temperature (52.5 °C), cycles of heating and recovery were carried out. Heated virus samples were titred by plaque assay and compared to an unheated virus control population, n=3 in duplicate, graphed mean±sem.