Human peripheral blood lymphocytes were treated with (top), or without (bottom) H₂O₂ for five minutes, fixed with Fixation Buffer, permeabilized with True-Phos™ Perm Buffer, then surface stained with CD3 Brilliant Violet 421™ and intracellularly stained with anti-ZAP70 Phospho (Tyr319)/Syk Phospho (Tyr352) (clone 1503310) Alexa Fluor® 488.