FIG. 6.

Assessment of H5-VN04 stability upon drying/storage during a 2- to 3-month period. H5-VN04-coupled biosensors were dried in different storage buffers, stored for 3 days, and assessed for binding to the homologous polyclonal ferret serum identified formulations containing sucrose as a potential condition to store HA-coupled biosensors in a dry format (A). Ten percent sucrose was selected for experiments to assess longer-term storage of biosensors. At days 12 and 62, biosensors were used to detect binding to a monoclonal antibody (B519M) that can neutralize by HI and thus detects a neutralizing antigenic epitope in the HA (B). Results show only a minimal loss of binding compared to that for biosensors loaded with freshly prepared recombinant HA. The viability of the dried HA after 76 days was also assessed by the biosensor's ability to bind the glycoprotein fetuin with and without preincubation with anti-H5-VN04 ferret serum (which detects a functional receptor binding site) (C).