FIG.1.

Membrane-associated cytoplasmic HSV capsids bind to microtubules in vitro. (A) Bouyant organelles were isolated from the cytoplasm of HSV K26GFP-infected cells. They then flowed into an imaging chamber, which contained prebound rhodamine-labeled microtubules. After an incubation of 5 to 10 min, unbound material was washed away, and the chamber was imaged using fluorescence microscopy. The upper panel shows microtubules in red and bound HSV-containing organelles in green. The lower panel is another representative field shown in black and white. Scale bar, 10 μm. (B) HSV was bound to microtubules as in A, and the chamber was then fixed in glutaraldehyde and prepared for transmission electron microscopy as described in Materials and Methods. This representative image appears to show HSV capsids partially or completely enclosed by an organelle (arrowhead) or adjacent to an organelle (black arrow) and in both cases attached to a microtubule (white arrow). Scale bar, 100 nM.