Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Heat stability of mutant viruses selected from the mutant virus library. After the third heat treatment, we performed plaque assays in AX4 cells, randomly selected 20 plaques (L1 to L20), amplified them in AX4 cells, and determined their virus titers (A) and HA titers (B) after treatment at 50°C for the indicated time periods. The mutations detected in the HA proteins of these viruses are presented in Tables 1 and 2.
