FIG. 8.

HPP does not degrade viral genomic RNA. (A) Detection of VP1 gene from pressure-treated MNV by RT-PCR. Viral genomic RNA was extracted from either HPP-treated or untreated MNV-1. The VP1 gene of MNV-1 was amplified by one-step RT-PCR, and PCR products were visualized by 1% agarose gel electrophoresis. (B) Detection of VP1 gene from pressure-treated viral genomic RNA by RT-PCR. Viral genomic RNA was extracted from MNV, and an equal amount of RNA was treated by HPP followed by RT-PCR. (C) Detection of VP1 gene from pressure-treated MNV contaminated by environmental RNases. MNV was purified and eluted in PBS buffer (not treated by DEPC). All other remaining steps were done under RNase-free conditions. These viruses were treated with three pressure levels, and viral RNA was extracted; this process was followed by RT-PCR. (D) Direct treatment of VP1 gene by HPP. The VP1 gene was amplified by RT-PCR, and an equal amount of purified VP1 gene was treated by HPP.