Fig. 7. Size analysis of endogenous Dd-STATb protein on a glycerol gradient. Cells at 4 hours of development in shaken suspension were treated with 100mM sorbitol for 30 minutes (Araki et al., 2003). A whole cell protein extract was then centrifuged through a 10%-40% glycerol gradient (Fukuzawa et al., 2001). We have previously calibrated this system using commercial size markers but additionally, in this experiment, the activated (dimeric) form of Dd-STATc was generated by the sorbitol treatment and this was used as an internal marker (see text).