Intracellular staining for IL-21 - (Jul/01/2011 )

Hi there! It is my first post in this forum

I just wonder if there is any of you here has done intracellular cytokine staining for IL-21 before? I have tried it for a couple of times of using PMA/ION for stimulation of PBMCs but still could not get any staining. Any advice would be greatly appreciated

Did you use Golgi-stop reagent (Brefeldin or similar)?

Also for T cell stimulation it is better to use plate-bound anti-CD3 mAbs together with soluble anti-CD28 mAbs.