The lyophilized product is shipped at ambient temperature and may be stored at +4¡C; prolonged storage at or below -20¡C. It is reconstituted by adding 1 ml sterile distilled water, spun down to remove insoluble particles, divided into small aliquots, frozen and stored at or below -20¡C. Prior to use, an aliquot is thawed slowly at ambient temperature, spun down again and used to prepare working dilutions by adding sterile phosphate buffered saline (PBS, pH 7.2). Repeated thawing and freezing should be avoided. Working dilutions should be stored at +4¡C, not refrozen, and preferably used the same day. If a slight precipitation occurs upon storage, this should be removed by centrifugation. It will not affect the performance of the product. Lyophilized at +4¡ C--at least 10 years. Reconstituted at or below -20¡ C--3-5 years. Reconstituted at +4¡ C--7 days.