The Good
Provides decent intracellular detection of phosphorylated STAT4 following IL-12 stimulation of human NK cells.
The Bad
There is no clear separation between positive and negative populations, so protocol optimisation is important. The staining protocol is relatively demanding, requiring a long methanol permeabilisation/incubation step (~1 h) and multiple washing steps, which can result in substantial cell loss. Staining is also somewhat delicate: it can be performed while vortexing the cells in tubes, or in a plate using a vortex mixer, but careful handling is required to obtain consistent results.
The Bottom Line
A decent option for detecting pSTAT4 intracellularly, but it requires careful protocol optimisation and handling. The relatively long staining procedure and cell loss during multiple washing steps may be limiting when working with low cell numbers.