A model for lipid raft heterogeneity in primary T cells. The solid line represents GM1 content of lipid rafts, and the thick dashed line represents cholesterol content. Thy1 and Lck localize in GM1-rich lipid rafts (darker gray bar), while LFA-1 partially localizes in cholesterol-rich rafts (lighter gray bar). Thick black bars represent lipid raft insolubility in Triton X-100 (1% and 0.05%) and Brij 35 (1%). MCD sensitive bar shows the portion of lipid rafts that is insoluble in 1% Brij 35 and sensitive to MCD treatment.