Lyophilized powder may be stored at -20 degree C. Stable for 12 months at -20 deg C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20 deg C. Reconstitued product is stable for 12 months at -20 deg C. For maximum recovery of product, certrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.