Flow-cytometry using the Anti-IL-9 antibody MH9A4 (TA386284). Human peripheral blood leukocytes were rested for 4 hours. The cells were fixed using 2% PFA, permeabilized using 0.5% Triton and stained with anti-Fluorescein IgG antibody (clone 4-4-20; isotype control, black line) or the rabbit IgG version of MH9A4 (TA386284, blue line) at a dilution of 1:100 for 1h at RT. After washing, bound antibody was detected using a goat anti-mouse IgG AlexaFluor® 488 antibody at a dilution of 1:1000 and cells were analyzed using a FACSCanto flow-cytometer.