1. Begin with 5 X 105 cells per ml to be fixed and examined. Place the cells in a 6-ml polystyrene Falcon tube (#2058).
2. Fix the cells as follow:
Spin cells down and wash in 500 ul of 1X PBS.
Resuspend in 500 ul Cytofix while vortexing.
Incubate in Cytofix for 30 minutes at RT.
Spin down the cells and wash in 1 mL of Perm Wash.
Resuspend in 1 mL of Perm Wash.
Incubate for 10 minutes at RT.
Spin down the cells and resuspend in 50 ul of Perm Wash.
3. Add 10 ul PARP PE.
4. Incubate in the dark for 30 minutes at room temperature.
5. Add 450 ul of Perm Wash solution.
6. Examine by flow cytometry.