Detection of LFA-1 in Brij 35–insoluble, MCD- and filipin-sensitive lipid rafts of primary T cells. (A) Primary T cells, untreated (-) or treated (+) with 10 mM MCD, were solubilized with 1% Brij 35 and subjected to sucrose gradient centrifugation. Fractions were blotted with corresponding antibodies. (B) Primary T cells were either untreated (-) or treated (+) with 0.1 mg/mL filipin, lysed with 1% Brij 35, subjected to sucrose gradient centrifugation, and fractions were probed with anti-CD18 (LFA-1). The results are representative of 3 independent experiments.