Biotinylated b-galactosidase is prepared from an enzyme of exceptionally high specific activity isolated from a special strain of E. coli. Unlike mammalian b-galactosidase, the activity of this E. coli enzyme is optimal at an alkaline pH, enabling it to be used free of interference from endogenous enzyme activity. For many applications, Avidin D followed by biotinylated b-galactosidase affords a highly sensitive system which can be used in a variety of enzyme immunoassays, including screening for monoclonal antibodies. One unit is 1 micromole o-nitrophenyl-b-D-galacto-pyranoside hydrolyzed per min. at 37 degrees C, pH 7.3.
Applications:
Suitable for use in ELISA. Other applications not tested.
Recommended Dilution:
Optimal dilutions to be determined by the researcher.
Activity:
746 units/mg protein
Storage and Stability:
Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 6 months at -20 degrees 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.