Figure 3From: Amino acid substitutions in the neuraminidase protein of an H9N2 avian influenza virus affect its airborne transmission in chickens Virus titers of airborne H9N2 AIV in an isolator. Air samples were collected simultaneously from the space of two isolators using an AGI-30 liquid sampler operated continuously for an optimized time of 30Â min at an airflow rate of 12.5Â L/min. Virus titer in the air was expressed as values of EID50/L air. Each color bar represented the every recombinant virus concentration in the air collected every two days from the beginning of 2 dpi in an independent experiment. No airborne virus was detected in the experiment for r01/NASS and r01/NA381 viruses.Back to article page