Ishikawa cells grown to 80% confluency were exposed to 1 mM DETANONOate for 2 h before cell harvest. Total cellular membranes were prepared by the ultracentrifugation of the cell lysate at 200,000 × g for 45 minutes. The cellular membranes were then separated by ultracentrifugation on 10 to 30% Optiprep density gradient at 100,000 × g for 16 h. Twenty fractions of 245 μl each were collected from top to bottom in the order of increasing density. (A) Distribution of DAF, caveolin1 and organelle markers Akt (plasma membrane), Rab5 (early endosomes), Syntaxin6 (Golgi bodies) were analyzed by western blot. (B) Densitometric analysis of relative abundance of DAF and organelle markers in different fractions of non-treated and NO exposed cells expressed as % of total density. (C) Densitometric analysis of relative abundance of caveolin1 and organelle markers in different fractions expressed as % of total density.