Hepatitis B Virus pre-S1 Antigen, Recombinant (HBsAg)

May be stored at 4 degree C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%). Store at -20 degree C. Aliquots are stable for at least 6 months at -20 degree C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.