Fig. 2. DIGs are characterized by their GM1 and caveolin content. DIGs were characterized in SaI/A^k cells by examining the localization of the typically DIG residents glycolipid GM1 and caveolin compared with the typically non-DIG-localizing protein ß-tubulin in the sucrose gradient. Cell lysates were fractionated on sucrose gradient and all fractions were immunoblotted with the respective Abs. DIG fractions correspond to fractions 3 and 4, whereas the soluble fractions correspond to fractions 7 and 8.