The Transcription Factor Fixation/Permeabilization solution can be used with the relevant antibodies to stain for transcription factors such as Foxp3 and intranuclear staining of cytokines, chemokines, and nuclear proteins. The concentrated solution should be used with the Transcription Factor Fixation/Permeabilization Diluent (cat#92555-00) and Permeabilization Buffer (cat# 92110-00).