PH1: An Archaeovirus of Haloarcula hispanica Related to SH1 and HHIV-2
Stability of PH1 virus to various treatments and conditions. Virus preparations (infected-cell supernatants in 18% (w/v) MGM) were exposed to various conditions, after which the virus titre was determined (in duplicate) on Har. hispanica cells. (a) The effect of temperature. Virus was incubated for 1 hr with constant agitation at temperatures between 4 and 100°C. (b) The effect of lowered salt concentration. Virus was diluted 1 : 1,000 in double-distilled H2O and incubated at room temperature, with constant agitation. Samples were removed at regular intervals. (c) The effect of pH. Virus was diluted 1 : 100 in Tris-HCl buffers at the different pHs and incubated with constant agitation for 30 min. (d) The effect of chloroform. Chloroform was mixed with virus (1 : 4 ratio) and incubated at room temperature with constant agitation. Samples were removed at regular intervals. Open square symbols indicate where virus titres were undetectable. Error bars represent one standard deviation of the average titre.