Analyzing endosomes in nonsectioned cells by transmission electron microscopy.
Cells take up plasma membrane proteins and lipids, together with plasma membrane-associated and fluid phase-endocytosed constituents, via distinct endocytic mechanisms. After having pinched off from the plasma membrane, endocytic vesicles fuse with endosomes; from there endocytosed molecules are sorted and transported by means of vesicular transport intermediates to distinct destinations, including lysosomes, the trans-Golgi network, and the plasma membrane. To study endosomal sorting processes, both light microscopic and electron microscopic techniques have been employed. A novel technique, involving 3,3'-diaminobenzidine (DAB) cytochemistry-based whole-mount immunoelectron microscopy, can be used to study the structure of endocytic compartments as well as the subendosomal/lysosomal distribution of relevant proteins in nonsectioned cells at high resolution.
Stoorvogel
Willem
W
Department of Biochemistry and Cell Biology, University of Utrecht, Utrecht, The Netherlands.
D015100:3,3'-Diaminobenzidine / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D019281:Dimerization; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism* / Q000648:ultrastructure; D006735:Horseradish Peroxidase; D006801:Humans; D007124:Immunoenzyme Techniques; D008247:Lysosomes / Q000000981:diagnostic imaging / Q000378:metabolism*; D008561:Membrane Fusion; D046529:Microscopy, Electron, Transmission; D016253:Microscopy, Immunoelectron; D021381:Protein Transport; D014168:Transferrin / Q000378:metabolism; D014463:Ultrasonography
D014168:Transferrin; D015100:3,3'-Diaminobenzidine; D006735:Horseradish Peroxidase