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. Author manuscript; available in PMC: 2010 Nov 1.
Published in final edited form as: Anal Biochem. 2009 Jul 19;394(1):117–124. doi: 10.1016/j.ab.2009.07.024

Figure 3.

Figure 3

Transmission electron microscopy of 3T3 MEF WT cells and subcellular fractions. (A) Whole cells are approximately 30 – 50 μm in diameter and show a clearly defined plasma membrane with normal subcellular architecture. (B) Following Balch homogenization, small tears are formed within the plasma membrane (black arrow) through which vesicles pass during centrifugation. The nuclear envelope is entirely intact (white arrow) and subcellular structures show few signs of disturbance. (C) The nuclear fraction consists of nuclei with unbroken envelopes and attached endosplasmic reticulum, both smooth and rough. (D) The large vesicle fraction contains a heterogeneous population of membrane-bound organelles 50 nm – 0.5 μm in size. Large, multivesicular structures are well-represented within this fraction (Inset). The small vesicle fraction contains membrane-bound structures 15 nm – 25 nm in size. Electron density within this population varies widely (Inset). (F) After NDG lysis the ghost fraction contains plasma membrane micelles as well as some electron dense protein clusters. (G) No membrane or protein structures are visualized within the cytosolic fraction.