Stability of recombinant bovine interferon-γ antiviral activity in the absence of stabilizing additives.

The stability of recombinant bovine interferon-gamma. (rbIFN-gamma) produced by a baculovirus expression system was investigated under different storage conditions: freezing-thawing and storage for 30 days at temperatures of -80, 4, 25, and 37 degrees C. Antiviral activity was not significantly decreased by freeze-thawing at least five times. Furthermore, although not statistically different, antiviral activity gradually decreased as temperature increased. These findings suggest that rbIFN-gamma possesses high thermal and freeze-thaw stability.