The lyophilized antiserum is shipped at ambient temperature and may be stored at +4 degree C; prolonged storage at or below -20 degree C. Dilutions may be prepared by adding phosphate buffered saline (PBS, pH 7.2). Repeated thawing and freezing should be avoided. If a slight precipitation occurs upon storage, this should be removed by centrifugation. It will not affect the performance of the antiserum. Diluted antiserum should be stored at +4 degree C, not refrozen, and preferably used the same day.