HEK293 cells transfected with expression vectors harboring target gene were harvested and washed with PBS twice. The cell pastes were re-suspended with ice-cold PBS containing mammalian cell protease inhibitor cocktail and further lysed with freeze-thaw cycles. After clarifying with 20,000 g centrifugation at 4°C for 30 min, the lysate was aliquoted, lyophilized, and stored at -80°C immediately. Protein concentration was determined by BCA kit (Thermo Scientific, Inc.) using BSA as protein standard. The gene overexpression in lysate was confirmed by Western blotting using anti-His tag antibody and/or target-specific antibodies and the lysate derived from HEK293 cells transfected with the empty expression vector was used as a negative control.
Specifications
Stability & Storage
Shipping
Including one vial of HEK293 cell lysate transfected with empty expression vector.
Storage/Stability
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.