Fig. 5.

Effect of solution pH on log loss of rHCMV-1 infectivity titer after short term storage at 4 °C in the presence of various excipient combinations. The rHCMV-1 stock was diluted 1:100 into various formulations (10 mM histidine buffer at pH 5.5, 6.0, 6.5, and 7.0 in presence of the indicated excipients) and stored at 4 °C for up to 8 days. The stability of rHCMV-1 in TNS buffer was also examined. The log loss of rHCMV-1 viral titer was calculated by subtracting the log (titer) of the respective −80 °C control samples in the same formulation from the log (titer) of the experimental sample. Stability data are an average of six measurements with the error bars representing the standard deviation.