Fig. 6. Accessible PtdIns(4,5)P₂ is not detected in transferrin-containing trafficking compartments. Texas-Red-conjugated transferrin (Tf-TR) was used as a marker for intracellular compartments of the endocytic pathway. NR6 WT cells transfected with either GFP-SH2 (A,B) or GFP-PH (C,D) were treated for 20 minutes with Tf-TR alone (A,C) or with Tf-TR and unlabeled EGF (B,D). Cells were visualized by confocal fluorescence microscopy.