How to prepare cell lysate for NADP/NADPH ratio assay?

Protocol: NADP/NADPH Ratio Assay, Cell Lysate, HL-60 cells

1. 1 mL of HL-60 cells (1∼2x10⁶ cells/mL)
2. Centrifuge to remove medium
3. Add 200 µL of lysis buffer to the cell pellet
4. Incubate for 15 minutes at 37°C
5. Centrifuge for 5 minutes to remove cell pellet
6. The supernatant can be used directly as your sample