Flow Cytometry Laboratory

Intracellular Labeling Protocol- Foxp3 eBiosciences Buffer Kit



Materials

First Wash Buffer (FWB)

450 ml PBS
50 ml ACD
2.25 ml 20% sodium azide in PBS
10 ml horse serum

Second Wash Buffer (SWB) FWB without horse serum

eBiosciences Foxp3 Buffer Kit (Cat. No. 00-5523-00)

10X Permeabilization buffer
Fixation/Permeabilization diluent
Fixation/Permeabilization concentrate

Perm/Wash solution: dilute 10X Permeabilization buffer 1:10 with distilled water. Make up just before use.

Fix/Perm solution: Dilute 1 part of Fixation/Permeabilization concentrate with 3 parts of Fixation/Permeabilization diluent. Make up just before use.




Protocol

  1. Add monoclonal antibodies to a 96 well V bottom plate for surface labeling. Monoclonal antibodies are typically used as 50 μl of 15 μg/ml stock per well.  Place plate on ice.
  2. Transfer 1-2 million cells in 100 μl FWB into each well.  
  3. Label surface epitopes using standard protocols.
  4. Add 200 μl Fix/Perm solution per well.
  5. Incubate cells for 30-60 minutes at 4˚ C in the dark.
  6. Pellet cells at 2000 rpm for 3 minutes, and aspirate buffer.
  7. Vortex plate at low speed to resuspend cells.
  8. Wash 2 times with Perm/Wash solution.
  9. Resuspend cells in 200 μl Perm/Wash solution.
  10. Add 50 μl anti-FoxP3 antibody diluted in Perm/Wash solution to each well.
  11. Incubate at 4˚ C in the dark for at least 30 minutes.
  12. Centrifuge 3 minutes at 2000 rpm at 4˚C  to sediment cells.
  13. Aspirate supernatant and vortex at low speed. 
  14. Wash 2 times with 200 μl Perm/Wash solution per well.
  15. Resuspend cells in 200 μl Perm/Wash solution
  16. Add 50 μl of secondary antibody diluted in Perm/Wash solution per well.
  17. Incubate at 4˚C in the dark for at least 30 minutes.
  18. Centrifuge 3 minutes at 2000 rpm at 4˚C  to sediment cells.
  19. Aspirate supernatant and vortex at low speed. 
  20. Wash 2 times with 200 μl Perm/Wash solution per well.
  21. Resuspend in 200 μl SWB and view on FC.