Intracellular Cytokine Staining (ICS) Protocol for FACS Analysis

This protocol provides a comprehensive method for the intracellular staining of lymphocytic cells for Fluorescence-Activated Cell Sorting (FACS) analysis. The procedure outlines the steps for restimulating cells using an OVA/SYRGL peptide or a PMA-Ionomycin control, which is then followed by formaldehyde fixation, saponin-based permeabilization, and targeted antibody staining. Upon completion, users can expect to successfully label specific intracellular cytokines, such as IFN-gamma, TNF-alpha, and IL-2, alongside extracellular markers including CD8 and CD44. These prepared samples will yield distinctly fluorescently labeled cell populations that are optimally prepared for flow cytometric acquisition and subsequent analysis.