Including one vial of cell culture supernatant of HEK293 cells transfected with empty expression vector.

Upon arrival, the lyophilized protein may be stored for 2 weeks at 4^°C. For long term storage, it is recommended to store desiccated below -20 ^°C in a manual defrost freezer. Following reconstitution, the protein may be stored for 2 weeks under sterile conditions at -20 ^°C.  For long term storage, it is recommended to make appropriate aliquots and store at -80 ^°C. Avoid repeated freeze-thaw cycles.