Testing Digitonin Mediated Cell Permeabilization with Trypan Blue
1. Dilute the digitonin stock to 0.016% in MEB2-P25 and perform a 2-fold serial dilutions five times (0.008%, 0.004%, 0.002%, 0.001%, 0.0005%) to make a panel of 6 different digitonin concentrations (at 2x final) in MEB2-P25 buffer.
2. Take 400,000 cells you wish to BH3 profile and resuspend in 40 uL of MEB2-P25.
3. Combine 5 uL of cells with 5 uL of the 6 digitonin concentrations.
4. Wait 5 minutes to allow permeabilization
5. Add 10 uL of trypan blue, mix, and transfer to a hemocytometer.
6. Permeabilized cells will appear blue under the microscope.
7. Select the lowest concentration of digitonin that results in 100% permeabilization.