True-Phos? Perm Buffer has been developed to permeabilize fixed peripheral blood mononuclear cells (PBMCs), lysed whole blood, cell lines, or splenocytes. Cells can be stimulated cytokines (e.g. IL-4, IL-6, etc.), antibodies (e.g. anti-CD3, clone HIT3a), or phorbol-12-myristate 13-acetate and ionomycin (Cell Activation Cocktail; Cat. No. 423301), and fixed with Fixation Buffer (Cat. No. 420801), or for whole blood, RBC Lysis/Fixation Solution (Cat. No. 422401). This buffer has been designed for use with antibodies for phospho-proteins (e.g. p-STAT6, p-ERK, etc.) and other intracellular targets (e.g. Cyclin B1, pan-STAT3, etc.). Not all cell surface markers are compatible with BioLegend’s True-Phos? Perm Buffer.